US3 SUNSPOTS PULLEYS
This eighth-grade science lesson is about sunspots and pulleys. The portion of the lesson on pulleys constitutes the ninth lesson in a sequence of 12 lessons on machines. The lesson is 51 minutes in duration. There are 33 students in the class.
| Time | Caption |
|---|---|
| 00:00:10 | Okay, do I have any others of these pages? |
| 00:00:13 | Here. |
| 00:00:14 | Going once. |
| 00:00:15 | Oh, I do. |
| 00:00:16 | Yeah. That's it. That's really great. |
| 00:00:17 | [ bell ] |
| 00:00:18 | Thank you. Can I have any others? |
| 00:00:23 | Miguel, sit down. |
| 00:00:25 | Audrey. Audrey, put them away. |
| 00:00:27 | What is this? |
| 00:00:29 | Audrey. |
| 00:00:30 | It's my (inaudible). |
| 00:00:31 | What? |
| 00:00:33 | It's what? |
| 00:00:34 | Audrey. |
| 00:00:35 | He's recording. |
| 00:00:36 | Thank you. |
| 00:00:37 | Oh, wait- I need to write my name on it. |
| 00:00:39 | Cool. |
| 00:00:40 | Is my name on it? |
| 00:00:41 | I didn't- |
| 00:00:42 | It's fine. I put your name on it. |
| 00:00:45 | Oh. Sorry. |
| 00:00:46 | Guys, get out your binder reminders. |
| 00:00:49 | Oh. I didn't do it. |
| 00:00:50 | Write down tonight's homework assignment. |
| 00:00:51 | Are we going outside and do sunspots? |
| 00:00:53 | Yeah. That's the plan. Audrey, sit down. |
| 00:00:55 | (inaudible) go to the office and get my- |
| 00:00:58 | Get what? |
| 00:00:59 | My binder reminder. |
| 00:01:00 | Why? What did you leave it up there for? |
| 00:01:03 | Because I just left it up there. |
| 00:01:05 | Where is it? I'll send Justin for it. |
| 00:01:08 | It's up there. |
| 00:01:09 | Where? |
| 00:01:14 | (inaudible) gardener. I have to go get it. |
| 00:01:16 | Okay. There you go. Justin will get it for you. You need to sit down. |
| 00:01:21 | (inaudible) |
| 00:01:24 | Her binder reminder. |
| 00:02:06 | What did I do? Oh, //my gosh. |
| 00:02:10 | //You were late. You were late. |
| 00:02:13 | I was not late. |
| 00:02:17 | You need to write down tonight's homework assignment. It says read pages 145 to 149. |
| 00:02:23 | On page 149, I'd like you to do questions one through four, please. |
| 00:02:27 | Number 18? |
| 00:02:28 | Questions one through four. Number 18. And as always write out the questions and the answers. What do you need, Miguel? |
| 00:02:35 | Nothing. |
| 00:02:37 | Cool. |
| 00:02:40 | Cindy, could you go sit in your actual seat? Thank you. Yes, Audrey? |
| 00:02:45 | (inaudible). |
| 00:02:50 | Yes, Audrey. |
| 00:02:51 | (inaudible) |
| 00:02:52 | Oh. I hate when you guys do that. |
| 00:02:56 | As soon as you've got that written down, we need our little sunspot data sheets, |
| 00:03:01 | but I can't remember whether we had some for today or whether we need to make some. |
| 00:03:06 | We need to make some. |
| 00:03:07 | We need to make some. |
| 00:03:08 | Okay. Then I'm gonna pass out a piece of paper to you. |
| 00:03:10 | Tear it in half like we've done before, take about an inch off the bottom, |
| 00:03:13 | and I'll pass out compasses so that we can get the sun's shape drawn before we head outside. |
| 00:03:23 | (Punch and munch) tomorrow. |
| 00:03:26 | Tomorrow. |
| 00:03:33 | I think I left enough for Matt so- |
| 00:03:44 | Cindy, can you wash that off your hand, please. There's a sink right behind you. |
| 00:03:48 | Did you go find Audrey's stuff yet? After you take roll. |
| 00:03:51 | TA:00] |
| 00:03:52 | Okay, that's cool. |
| 00:03:53 | We need another one for Matt. |
| 00:03:54 | Okay. I thought I gave you one, but- |
| 00:03:55 | (inaudible) one for Matt. |
| 00:04:04 | There's one. Pass that one back to Matt, would you? |
| 00:04:06 | Mr. Melville, are you gonna watch this tape after? |
| 00:04:09 | Nope. |
| 00:04:10 | Okay. Good. |
| 00:04:11 | I'll have no idea. Why? Are you planning on doing some rude symbol while my back is turned? |
| 00:04:17 | No. |
| 00:04:18 | Is that it? |
| 00:04:19 | No. Because like if we do something then you're gonna see it then we're gonna get caught and get in trouble anyway. |
| 00:04:21 | I see. |
| 00:04:22 | I was just asking. |
| 00:04:24 | No. I will never see it. |
| 00:04:28 | You're funny. |
| 00:04:37 | Take two, pass it back. And there's one extra for Matt. |
| 00:04:41 | Cindy, once it's washed off, you can sit down. |
| 00:04:45 | I need a towel. |
| 00:04:46 | I see. There's some next to the sink over there. |
| 00:04:51 | Take two, and pass the rest back. |
| 00:04:53 | Okay. |
| 00:04:54 | Set the compass at four and a half centimeters, please. |
| 00:04:58 | Audrey, put that away or I'm gonna read it out loud to everybody. |
| 00:05:01 | Okay, okay, okay, okay, okay, okay, okay. |
| 00:05:03 | On tape. |
| 00:05:04 | Read it out loud. |
| 00:05:05 | Thank you. |
| 00:05:06 | That'll be the most funniest moment. |
| 00:05:08 | That would make my day. |
| 00:05:10 | Exactly. |
| 00:05:11 | Then we can catch her reaction on tape, too. That'd be really great. |
| 00:05:17 | Miguel, it's just a compass. |
| 00:05:19 | Separate them in two halves, take about an inch off the bottom, please. |
| 00:05:22 | I'll be there anyway. |
| 00:05:23 | Draw your sun circle about in the center. |
| 00:05:26 | I'm just kidding. |
| 00:05:27 | Esther, how much is like Alfred's? |
| 00:05:32 | Fold it in half, turn. |
| 00:05:34 | That's all you had to do? |
| 00:05:36 | Yeah. That's it. That's it. |
| 00:05:41 | Where's Randy? |
| 00:05:43 | He went to the nurse's office. |
| 00:05:45 | I forgot. |
| 00:05:46 | He wasn't feeling well. |
| 00:05:47 | Excuse me. |
| 00:05:50 | (inaudible) |
| 00:05:56 | Leave him alone, Audrey. Just a little. |
| 00:06:04 | Mr. Melville? |
| 00:06:05 | Yeah. |
| 00:06:06 | (inaudible) Jack's name? |
| 00:06:08 | Uh, you can actually draw a line through Jack's name on there and, uh- was that it for this class that transferred to the high school? |
| 00:06:15 | What? |
| 00:06:16 | Was it just Jack? I think it was just Jack actually so that would be fine. |
| 00:06:36 | Which one is number one, Justin? Which one of those is number one? |
| 00:06:41 | I got number two. |
| 00:06:42 | Okay, thanks. |
| 00:07:00 | (inaudible) put it on- how many centimeters? |
| 00:07:02 | Four //and a half. |
| 00:07:03 | //Four and a half centimeters. |
| 00:07:07 | That ain't gonna be (inaudible). |
| 00:07:08 | How do you know? |
| 00:07:09 | Paper. |
| 00:07:12 | Carly, the camera loves you. |
| 00:07:17 | Yes. |
| 00:07:18 | Can we do the other circle for the other paper too, Mr. Melville? |
| 00:07:21 | Uh, yes. Please do both circles because I don't want to have to do this again tomorrow. I'd just like to go out and get the sunspots real quick. |
| 00:07:29 | Mr. Melville, do you want us to act like perfect kids right about now? |
| 00:07:32 | You know what? Every single day I would like you to act like perfect kids. If- |
| 00:07:36 | Well, I'm just saying- |
| 00:07:37 | If today is the best you can do for being perfect, //I'll take it. |
| 00:07:39 | //(Keep it on me). |
| 00:07:40 | That would be great. Yes, thank you. |
| 00:07:41 | Just so we make you look good on, you know, the little camera thing. |
| 00:07:45 | Camera one and camera two. Yes. |
| 00:07:46 | What cameras? |
| 00:07:47 | There's two cameras? |
| 00:07:49 | Fade to Audrey. There we go. |
| 00:07:51 | Okay. Let's get them separated, get the covers off, and find a space in the sun. Audrey? |
| 00:07:58 | What time is it? |
| 00:08:00 | Stop. Stop. |
| 00:08:02 | And it'll probably be about 1:30 or 12:30 when we have them set up out there. |
| 00:08:09 | Here. |
| 00:08:11 | That's beautiful. |
| 00:08:16 | (You have a) compass right there. |
| 00:08:19 | Okay, put circles on both data pieces, today and tomorrow. |
| 00:08:26 | Put sunspots at the top, name, date, and the period, and the time of 12:30, which is about when we will be out there. |
| 00:08:33 | Mr. Melville? What time- |
| 00:08:34 | Yes? |
| 00:08:35 | What time-//how- how- |
| 00:08:36 | //Can we go out there when we're done, Mr. Melville? |
| 00:08:37 | Well, we're all- we're all heading out there. |
| 00:08:42 | Okay. Tops off. Let's get the stands from the telescopes and head on out. |
| 00:08:46 | (inaudible) //My temperature is 102. |
| 00:08:47 | //Okay. Gather your stuff. |
| 00:08:49 | Okay. Seriously? That's probably why you don't feel well, Randy. |
| 00:08:51 | What happened to Randy? |
| 00:08:52 | He's got a temperature of 102. So that's probably why he doesn't feel well. |
| 00:08:55 | (inaudible) |
| 00:09:04 | Let's go, folks. Bring them outside. Find a spot in the sun. |
| 00:09:18 | Goodie, goodie. |
| 00:09:33 | Let's do it right here. |
| 00:09:34 | Where's Kevin at? |
| 00:09:37 | The sun's right here. |
| 00:09:38 | Where did you see that? I never told him that- or told her that you liked her. I never said that she liked John. |
| 00:09:46 | Mark your sunspots and track one moving west, please. |
| 00:09:52 | Come on, you guys. Everybody else is out. Let's go. |
| 00:09:54 | Come on. |
| 00:10:03 | Hurry up. |
| 00:10:05 | Hurry up. |
| 00:10:09 | Hurry up. |
| 00:10:10 | Please be careful with them. Come on, Miguel. |
| 00:10:13 | Okay. Wait. |
| 00:10:15 | Justin. |
| 00:10:16 | I'm learning very quickly. |
| 00:10:20 | Very slowly. |
| 00:10:21 | Okay. Any of these areas in the full sun is fine as long as you're not behind tree shadows. |
| 00:10:25 | Right here. |
| 00:10:26 | That would be fine. That- that's fine. |
| 00:10:28 | Cindy? Cindy? Cindy? |
| 00:10:33 | No. We're going over here. Look, I didn't write- |
| 00:10:36 | What? |
| 00:10:39 | I have it right here. |
| 00:10:40 | It needs- Monica, //it needs a little adjustment just so it'll get it more centered. |
| 00:10:41 | //We can do it here, but it's not gonna show. |
| 00:10:47 | Are you in my group? |
| 00:10:59 | Mine's not working very well, Mr. Melville. |
| 00:11:02 | You're getting it. |
| 00:11:03 | Not really. |
| 00:11:05 | Did you make the shadow disappear on the (inaudible) first? |
| 00:11:07 | I don't no. |
| 00:11:10 | There should be no shadow up there. So can you tilt it left and right //so that the shadow goes away? |
| 00:11:14 | //What are you doing? You're not supposed to screw it. |
| 00:11:16 | (inaudible). |
| 00:11:17 | No, //you're not. |
| 00:11:18 | //Diane, I need help. |
| 00:11:19 | You're not? |
| 00:11:20 | No. You're supposed to be able to move it around. |
| 00:11:22 | Okay, now you got shadow on this side, okay? |
| 00:11:25 | You're almost there. Now you just need to tilt it a little bit to make- there you go. |
| 00:11:31 | Now, you should be able to see spots here. If you line those up in the center of the target, you should have your sun. |
| 00:11:40 | There it is right there. |
| 00:11:42 | Little sunspot. |
| 00:11:43 | (inaudible) need small adjustments. |
| 00:11:54 | And you're all set. |
| 00:11:57 | Please mark your sunspots and track one of them moving west. Yeah? |
| 00:12:01 | Can I get a drink of water because my- |
| 00:12:02 | Sure. There's a sink right over there- I mean a faucet right over there. |
| 00:12:06 | I can't see them (inaudible). |
| 00:12:08 | Mr. Melville, is this a sunspot; the big one right there? |
| 00:12:11 | This just doesn't work with my //(inaudible) |
| 00:12:13 | //I don't think so. |
| 00:12:16 | Are you serious? |
| 00:12:18 | Flip it around. |
| 00:12:19 | Are you talking about this thing right there? |
| 00:12:20 | Yeah. |
| 00:12:21 | I think that's just, uh- stuff on your mirror or your lens. |
| 00:12:25 | Watch. |
| 00:12:26 | Done yet? |
| 00:12:29 | Mark the other ones over there. |
| 00:12:30 | It's the small black specks you're //looking for. |
| 00:12:31 | //Hey, Miguel. It's the group. |
| 00:12:35 | Where's Randy? |
| 00:12:38 | Are you guys done yet? |
| 00:12:39 | I am. |
| 00:12:41 | Mr. Melville, I need help. |
| 00:12:42 | Okay. Did we get them tracked west? |
| 00:12:47 | Move. |
| 00:12:48 | No //(inaudible). |
| 00:12:49 | Did //we? Okay. So you guys haven't done yours yet? |
| 00:12:51 | We just started. |
| 00:12:54 | Okay. Well, you're really close. See these white spots here? |
| 00:12:57 | Yeah. |
| 00:12:58 | Okay. All I need is in the center of the target, see. |
| 00:13:05 | I didn't know that. |
| 00:13:07 | That's it. So there you go. |
| 00:13:10 | So that was for- |
| 00:13:11 | Now you need to mark them. |
| 00:13:13 | (inaudible). |
| 00:13:14 | Oh, that's ours? |
| 00:13:17 | Where's yours? |
| 00:13:18 | Right there. |
| 00:13:19 | Okay. Are we gonna mark our sunspots and track them west? |
| 00:13:23 | Track them west? |
| 00:13:25 | You need to track one of them moving west. |
| 00:13:27 | I'm done. |
| 00:13:28 | Like we learned how to do on Monday. |
| 00:13:29 | Oh, okay. |
| 00:13:30 | Then we go put them back together? |
| 00:13:31 | Just wait. We'll all go back in in about a minute or so. |
| 00:13:35 | Wait. We got to find out which way is west. |
| 00:13:40 | South, east, west. |
| 00:13:44 | Audrey? |
| 00:13:50 | Audrey, what are you doing going into other people's classrooms? |
| 00:13:53 | I'm not. |
| 00:13:55 | You're standing there with the door wide open. What are you doing? |
| 00:13:58 | Because Beatrice was talking to me and Brenda. |
| 00:14:01 | Stay away. |
| 00:14:02 | Ladies? Come here. |
| 00:14:04 | I'm done. |
| 00:14:05 | That's great. Did you find- you didn't get one moving west. |
| 00:14:08 | Yes, I did. |
| 00:14:09 | No, you didn't. |
| 00:14:11 | What's west? |
| 00:14:12 | The direction that the sunspots move. |
| 00:14:13 | When you put it on there- |
| 00:14:16 | When you put it on there, you're supposed to let the sun move and make a mark for one of your sunspots as it moves. |
| 00:14:22 | It was this one. |
| 00:14:23 | Then how come there's not a series of marks? |
| 00:14:25 | Because I didn't leave it there. |
| 00:14:26 | Okay. You got to mark them, and that way will show you the direction west. |
| 00:14:35 | Hey, folks. You got to mark not only your sunspots. |
| 00:14:38 | You also have to track them moving west so you know which way your image is oriented so please track one of your sunspots moving west. |
| 00:14:50 | Mr. Melville, which way is west? |
| 00:14:52 | Well, that's what you got to figure out on the- |
| 00:14:54 | Wherever the sunspots are moving. |
| 00:14:55 | Where the sunspots are moving is west. |
| 00:14:57 | I know. I (always) make a little arrow. |
| 00:14:59 | Okay. Well, then that would be west. That would be fine. |
| 00:15:09 | Are you guys about finished or are you just goofing off? |
| 00:15:12 | We're just about finished. |
| 00:15:13 | Okay. |
| 00:15:14 | (Just set it down in the middle.) |
| 00:15:17 | (inaudible) my- |
| 00:15:18 | All right. They just copied it all off of you instead of actually doing it? Oh, that's so helpful. Okay, folks. |
| 00:15:29 | Let's get your telescopes and bring them back in. |
| 00:15:39 | One of you guys get the other half, Cindy. |
| 00:15:50 | Put them together, get the covers on, bring them back up to my desk. |
| 00:15:54 | Okay, then- |
| 00:15:55 | Audrey, why? |
| 00:15:57 | Because- |
| 00:16:07 | Matt, Rupert. Come on, you guys. |
| 00:16:23 | Esther, who's sitting out there still? |
| 00:16:26 | Hey, Ian. |
| 00:16:27 | Come on, Ian. |
| 00:16:29 | Ian? Al puerta. Come on, doggie. |
| 00:16:34 | Don't, Miguel. |
| 00:16:35 | That's enough, Miguel. |
| 00:16:41 | That's funny. |
| 00:16:48 | Let's get them back together, cases on. Bring them up front. |
| 00:16:58 | Justin, would you collect all the compasses? |
| 00:17:00 | Please send the compasses to the front of the room so Justin can pick those up. |
| 00:17:11 | Don't just throw it, Audrey. |
| 00:17:14 | Audrey. Audrey. |
| 00:17:18 | I'll take it. Thanks. |
| 00:17:22 | Huh? |
| 00:17:27 | My name is Justin. |
| 00:17:29 | Justin. Justin Timothy. |
| 00:17:33 | Justin Timothy. Timothy. Justin Timothy. |
| 00:17:40 | Oh. This is your (inaudible) class? |
| 00:17:42 | Uh, last year, yep. |
| 00:17:43 | So was Muriel, huh? |
| 00:17:44 | Yep. She was in my algebra class. |
| 00:17:49 | We gave stuff away in there, huh, Muriel? |
| 00:17:52 | Last year's algebra class. |
| 00:17:54 | Just like gave you stuff, remember? |
| 00:17:55 | Oh, yeah. |
| 00:17:57 | Yeah. She's looking at you in the picture. |
| 00:18:04 | Like candy bars and sodas, remember? |
| 00:18:06 | (inaudible) |
| 00:18:07 | Yep. |
| 00:18:10 | I need you guys to take out the lab sheet that we went over yesterday, please. |
| 00:18:31 | I remember somebody paid like three thousand dollars for a cup of soup or something like that, remember, in the secret bags. |
| 00:18:38 | Remember the ones we rolled up and stapled shut. That was funny. |
| 00:18:40 | I need one. |
| 00:18:41 | They're on the counter up here. Folks, get your labs. Find your spots, please. |
| 00:18:49 | What the (inaudible)? |
| 00:18:51 | Carly, watch your mouth, please. |
| 00:18:53 | Okay. Sorry. |
| 00:18:55 | You want to die there? (inaudible) here? |
| 00:18:59 | Matt, find your seat. |
| 00:19:00 | Liar. |
| 00:19:01 | (inaudible) |
| 00:19:05 | And you're telling the teacher why? |
| 00:19:10 | (inaudible) |
| 00:19:12 | They go in the bag on my desk. Can you do that for me, please. Shh. |
| 00:19:18 | Always in my face. |
| 00:19:19 | Oh, my gosh. |
| 00:19:21 | Okay, folks. I need your attention up here, please. |
| 00:19:23 | I wasn't jamming it. Oh, my God. (inaudible). |
| 00:19:32 | Tom. |
| 00:19:35 | Esther. |
| 00:19:41 | Okay. Everyone should have the "Pulley Potpourri" sheet out in front of you; the lab sheet. |
| 00:19:46 | Who thought of that name? |
| 00:19:48 | I did. It's my lab. |
| 00:20:16 | Shh. We're gonna get started on the lab today. |
| 00:20:23 | Shh. Folks, I need your attention up here, please. |
| 00:20:28 | I'm glad you guys are having so much fun coloring inside the letters, but (if) I could get your attention up here, I would really appreciate it. |
| 00:20:39 | We went over this yesterday. I'm just gonna recap it today because it's been 24 hours, and I know you forgot. |
| 00:20:48 | You're just gathering three pieces of data from each pulley setup. |
| 00:20:53 | You're gathering the effort distance, the effort force and the resistance force. |
| 00:21:00 | As I went over yesterday, you measure the resistance force just by picking the weight up with the scale, |
| 00:21:10 | and you measure the effort distance by using the ruler in centimeters to measure how far you pull the string |
| 00:21:20 | when you lift the weight by 10 centimeters. |
| 00:21:23 | The resistance distance in every case is 10 centimeters. |
| 00:21:28 | If I can have your attention back here- |
| 00:21:33 | just quickly go over this for the first setup again. |
| 00:21:36 | There are two rulers back at the station. |
| 00:21:44 | You'll be using both of them at the same time. |
| 00:21:47 | One person is gonna be measuring resistance distance; one person is gonna be measuring effort distance. |
| 00:21:53 | So you'll have one person using the centimeter side of the ruler. There's an inches side. |
| 00:22:00 | Don't use the inches; use the centimeters. They're gonna be measuring how high the bottom of the weight goes up. |
| 00:22:07 | When it's at 10 centimeters, that's as far as you're going. |
| 00:22:11 | While they're doing that, the person applying the effort to the simple machine, the person pulling on the string, |
| 00:22:20 | is gonna be measuring how far they have moved the string to raise the weight ten centimeters. |
| 00:22:28 | Now, some people in earlier classes were just writing down the numbers on here. |
| 00:22:34 | They would just- be holding them here and go, "Oh, that's 55." |
| 00:22:37 | That's not how it works. It's how far it moves. |
| 00:22:41 | So when the person is reading the resistance and they say, "Oh, that's 10 centimeters," on this thing, then you'll stop. |
| 00:22:48 | Where did you start? Where did you end? |
| 00:22:51 | If you started at 55 and went to 60 or went to 45, |
| 00:22:56 | depending on how you turned, how far would that be? |
| 00:22:59 | Say, you started at 55, and you pulled the string down to 60 on the ruler. How far would that be? |
| 00:23:05 | Five. |
| 00:23:06 | It would be five centimeters. Say, you started at 55, and it went to 45. How far would that be? |
| 00:23:12 | Ten centimeters. |
| 00:23:13 | It would be 10 centimeters. So it's how far you exert the force. |
| 00:23:19 | Audrey. It's the distance over which you apply the effort. |
| 00:23:26 | That's what effort distance is. |
| 00:23:28 | So if you start here and extend it that far, that's the effort distance. |
| 00:23:33 | A couple things to be aware of when you're doing your measurements. |
| 00:23:37 | If you pull it at an angle, your measurements won't be very accurate |
| 00:23:41 | so you want to make sure that you're pulling straight down in the direction that you are measuring. |
| 00:23:47 | Secondly, you want to make sure that, uh, when you're measuring the force you're also pulling straight down. |
| 00:23:54 | Straight down really helps on this lab. All right. So that's effort distance. |
| 00:23:58 | Probably one of the harder things to measure in the lab. We went over- we went over resistance distance. |
| 00:24:05 | What is it for every experiment that we're doing? |
| 00:24:07 | Newtons. |
| 00:24:09 | That's force, as in Newtons. But what's the resistance distance? Look on your lab. It's already filled out. |
| 00:24:15 | Ten- |
| 00:24:16 | Ten centimeters. |
| 00:24:17 | It's 10 centimeters. So 10 centimeters is how far we're lifting the weight up. |
| 00:24:21 | How far we pull this to lift the weight 10 centimeters is our effort distance. |
| 00:24:25 | The forces- I went over those yesterday. Got to zero these things. |
| 00:24:29 | The resistance force is just how much the resistance weighs, and as you guys just said a second ago, we are measuring it in what? |
| 00:24:36 | Newtons. |
| 00:24:37 | We are measuring it in Newtons. Estimate to the closest quarter Newton. |
| 00:24:41 | For effort distance- again, I showed you that yesterday- you need to tie a loop in the string, you need to zero it out upside down, |
| 00:24:49 | and you're gonna pull, and it works again much better if you pull upside down. |
| 00:24:54 | If you pull upside down- I'm sorry. Not pull upside down. |
| 00:24:56 | Pull straight down. If you pull straight down, you'll get much more accurate measurements. |
| 00:25:01 | If you do it off to the side, it just, uh- it's not gonna be as accurate, and again estimate to the closest quarter. |
| 00:25:06 | Those are the only three things you're doing for each pulley setup. There's four pulley setups. |
| 00:25:11 | You're not gonna get them all done today. You might not even get the first one done today. That's okay. |
| 00:25:17 | It's better that you get accurate data than that you just rush through all of these. We got time. |
| 00:25:22 | We're gonna spend a number of days on this. |
| 00:25:25 | Mechanical advantage, lastly. When we've got all your data, we're gonna go back and do mechanical advantage, |
| 00:25:31 | but you gotta- have to have good data so don't worry about mechanical advantage yet. |
| 00:25:35 | All right. At this time I'm gonna divide you up into 10 groups and send you to a station. |
| 00:25:40 | Get started on- well, you can do any of the pulley setups you want. |
| 00:25:43 | It doesn't matter whether you start with the first one or not, but let me sort of divide you guys up here. |
| 00:25:53 | That'll actually work out just, uh, fine. |
| 00:25:57 | Cindy, I'm gonna go ahead and, uh, put you and Matt with Miguel, and you guys will be at the first station over there. |
| 00:26:04 | Don't kill each other. Um, Diane, you guys are gonna be here on the other side of this first station. |
| 00:26:11 | Cassandra, you guys will be on this side of the first station. |
| 00:26:13 | Carly, you guys will be across from Matt's group. Audrey, you guys will be at this third station over here. Rupert? |
| 00:26:21 | Yes. |
| 00:26:22 | You guys will be just across from that. |
| 00:26:27 | Sheila and Eleanor, you guys will be where Cindy is, working at that station. |
| 00:26:31 | And, Josh and Muriel, you'll be just across from that. |
| 00:26:35 | And- let's see- Andrew and Zeb, you guys will be at this station back here, and you guys will be at the very last station on the end. |
| 00:26:42 | Okay. Let's head to our stations. Take your data table. Let's get them set up and get to work. |
| 00:26:47 | How much are these worth? |
| 00:26:49 | I think those were worth 50, but- |
| 00:26:54 | is there anything over 50? |
| 00:26:57 | I don't know. |
| 00:27:00 | I think it was just 50, so- |
| 00:27:03 | Okay. |
| 00:27:04 | Go ahead and put 50 on there. |
| 00:27:18 | There are knots in your string other than the one at the end. |
| 00:27:22 | You're gonna want to get those out. They don't go over the pulley well. |
| 00:27:27 | Are we right here? |
| 00:27:28 | Yep. |
| 00:27:29 | All right. |
| 00:27:37 | You guys are sort of working at different ends here, okay? |
| 00:27:41 | Like this? |
| 00:27:42 | You probably want to put the loop through. It doesn't- it doesn't really matter. |
| 00:27:46 | Oh. |
| 00:27:47 | But the loop hooks onto the weight. It's just you have to pull a lot more string through if you put the- better bring the string through first. |
| 00:27:56 | You can't just go like this and then- |
| 00:27:58 | Sure. You can. That's fine. |
| 00:27:59 | Put that weight up. |
| 00:28:03 | (You can ask me more, like, gently.) |
| 00:28:05 | Right here. |
| 00:28:06 | Where's the weight? This hooks around it? |
| 00:28:10 | Yeah. This hooks through. |
| 00:28:12 | (inaudible) |
| 00:28:14 | //It falls off. |
| 00:28:15 | //You got to keep the string on the pulley though. |
| 00:28:17 | Mr. Melville? |
| 00:28:18 | Yes? |
| 00:28:22 | Do you want us to do something with 41- the 41 part? |
| 00:28:27 | I have no idea what you are talking about. |
| 00:28:30 | How do we do effort force? |
| 00:28:32 | You tie a loop in the string and pull down when you're lifting the weight up. |
| 00:28:35 | Okay. |
| 00:28:36 | And see what reading you get. |
| 00:28:37 | Okay. |
| 00:28:39 | What do you want? |
| 00:28:44 | How did you get effort distance on there, Zeb? |
| 00:28:47 | (This side)? |
| 00:28:48 | You just- yeah. You need the difference. |
| 00:28:53 | So what's the difference between 57 and 41? |
| 00:28:58 | We need, uh- where is the ruler? |
| 00:29:00 | That thing- |
| 00:29:01 | Stop. |
| 00:29:02 | Oh. Where-? |
| 00:29:04 | (inaudible) this thing, that we went to yesterday- |
| 00:29:07 | Okay. |
| 00:29:08 | 'Cause that's what they said to us. They said that- |
| 00:29:09 | (shall I) measure it? |
| 00:29:11 | She has to measure how far hers went while you're measuring that. |
| 00:29:19 | Actually, the up- |
| 00:29:23 | Sheila, you're measuring how far your hand moved while she lifted that. |
| 00:29:30 | You want to- you want to start with it on the ground and start at something even, and when she says: |
| 00:29:36 | "Oh, that's 10 centimeters," then you look at how far you went. |
| 00:29:41 | All right. |
| 00:29:42 | Okay? |
| 00:29:43 | Oh. Is that effort distance? |
| 00:29:44 | So you start- it's how far the effort string goes. Yeah, that's effort distance. |
| 00:29:47 | Mr. Melville? |
| 00:29:48 | Yes? |
| 00:29:49 | What is it if it is from 50 to the one right here? Do we count one, two, three, or these little ones? |
| 00:29:53 | Well, the little ones are what? The big ones are centimeters. What are the little ones? |
| 00:29:59 | Millimeters. |
| 00:30:00 | Okay. They are millimeters, or tenths of a centimeter. So it would be- it would be point something. |
| 00:30:05 | You are trying to measure accurately, yeah. To the tenth would be fine. |
| 00:30:18 | You're gonna flip it. |
| 00:30:20 | I'm confused. |
| 00:30:22 | Which one? |
| 00:30:23 | All right. Put your hand up there somewhere. |
| 00:30:25 | What are we supposed to do? Just pull up and be like: "Woo, look how far it went?" |
| 00:30:28 | Yeah. That's it. |
| 00:30:30 | No, seriously- |
| 00:30:31 | You're supposed to actually measure some stuff along the way, and what would that be? |
| 00:30:34 | //Then what do we do after that? |
| 00:30:35 | //Wait up. Dude, just leave it this. |
| 00:30:37 | What's that? |
| 00:30:38 | Hold it, Audrey. |
| 00:30:39 | All we do is pull it up? That's it? |
| 00:30:41 | Oh. |
| 00:30:43 | Hold it. |
| 00:30:44 | And how far are you supposed to //lift it? |
| 00:30:45 | //Hold it. That girl- |
| 00:30:46 | Ten centimeters. |
| 00:30:47 | Okay. So when that's being lifted 10 centimeters, you want to know how far //you had to pull this down. |
| 00:30:50 | //That's what I'm saying. Hold it. |
| 00:30:53 | Which means you need to- |
| 00:30:54 | Where do you start from? |
| 00:30:55 | you need to measure. You can start from anywhere you want because it matters where you go to. |
| 00:31:00 | Sixty. |
| 00:31:01 | So I'd start at something even. |
| 00:31:02 | Sixty. |
| 00:31:03 | But it has to be straight down, and you have to know where you started. Audrey. Audrey, it's gonna fall. |
| 00:31:08 | Start at 60. |
| 00:31:09 | All right. Hold it from up here. |
| 00:31:10 | But you got to hold it somewhere so that you can pull. |
| 00:31:13 | Okay. Ready? |
| 00:31:15 | Oh, my god. You're //supposed to hold this right here. |
| 00:31:17 | //You got to measure- measure it while you do it, Audrey. |
| 00:31:20 | You do it. |
| 00:31:21 | (inaudible) |
| 00:31:22 | Yes. |
| 00:31:23 | How do we (inaudible)- |
| 00:31:24 | It's so frustrating working with a blonde. |
| 00:31:25 | Don't worry about that yet. We're gonna do that together once we got our data. |
| 00:31:29 | Audrey, just measure while you pull down. |
| 00:31:31 | I don't understand it. |
| 00:31:32 | Come here. |
| 00:31:33 | You have to write on this page, okay? Just this page. |
| 00:31:35 | Okay. |
| 00:31:36 | I wrote there. |
| 00:31:39 | Audrey, let's say you started there, and by the time that thing was 10 centimeters off the ground you were here. How far did it move? |
| 00:31:49 | I know how- |
| 00:31:50 | //How far did it move? |
| 00:31:51 | //I understand it. |
| 00:31:52 | I started at 50, I went down to 44. How far did it move? Or you can do it this way if you like that better. |
| 00:31:59 | Yeah. Just take my pen. |
| 00:32:00 | Started at 50, and I went to //64. |
| 00:32:01 | //I don't mind. |
| 00:32:02 | How far did it go? |
| 00:32:03 | Ask him. |
| 00:32:04 | Ten. Twelve. |
| 00:32:05 | Fifty to 64 is ten? |
| 00:32:06 | Fourteen. |
| 00:32:07 | Okay. So it would have been 14 centimeters, right? That's all you're doing. But you're- |
| 00:32:11 | But then where do you write it down? |
| 00:32:12 | I know. |
| 00:32:13 | Under "effort distance." |
| 00:32:14 | Okay. We need your help. |
| 00:32:16 | But guys, I wasn't doing it for you. It was just an example of how to read it. |
| 00:32:19 | That's what I'm saying- |
| 00:32:20 | Okay-? |
| 00:32:21 | I don't know how- |
| 00:32:22 | You can't write down 14. |
| 00:32:23 | When this is 10 centimeters off the ground, you want to know how far this string was pulled to lift this 10 centimeters off the ground. |
| 00:32:32 | That's what you're measuring. |
| 00:32:34 | Mr. M.? |
| 00:32:36 | Ian, go back to your spot. |
| 00:32:37 | We need to show you. |
| 00:32:38 | What? |
| 00:32:39 | You can't show on the other side //measuring (inaudible)? |
| 00:32:40 | //Mr. Melville, I don't //get this. |
| 00:32:41 | //How do you do effort force? |
| 00:32:42 | Mister- |
| 00:32:43 | Tie a knot in the string. |
| 00:32:44 | Okay. |
| 00:32:45 | Pull it with the scale. Read the reading in Newtons. |
| 00:32:48 | Oh. Okay. |
| 00:32:49 | So- thanks. |
| 00:32:51 | We need to pass this back? |
| 00:32:53 | Uh, yeah. Pass everything back. That's cool. Thanks. |
| 00:33:02 | Mr. Melville? |
| 00:33:03 | What's that? |
| 00:33:05 | (inaudible). |
| 00:33:06 | Uh, I- it's been- it's been in there for a while. I've already seen it so yeah. |
| 00:33:10 | Take it right here? |
| 00:33:11 | Yes, ma'am. |
| 00:33:12 | He called me first. |
| 00:33:15 | Like on this again- because we were doing this on this and we hooked it up to here. |
| 00:33:18 | No. |
| 00:33:19 | I mean- //I mean, I was listening to you but I kind of- |
| 00:33:20 | //We did this. We did that. |
| 00:33:23 | You need three pieces of data. Weigh this thing. That's resistance force. |
| 00:33:26 | Off this? |
| 00:33:27 | Tie a loop here, pull it down with the scale. That's effort force. Lastly, lift this 10 centimeters off the ground by pulling here. |
| 00:33:36 | And measure how far you pull this to lift this 10 centimeters off the ground. |
| 00:33:43 | This is the effort into my string so how far I pull it is gonna be what? |
| 00:33:47 | Ten centimeters, isn't it? Same as the bottom. |
| 00:33:49 | Well, that's what you are gonna find out. |
| 00:33:50 | Oh. Okay. |
| 00:33:51 | But you're gonna find that for most of the (pull) setups it's not the same, okay? |
| 00:33:55 | Tie it up here? |
| 00:33:57 | No- yeah, for the force, yeah. |
| 00:34:00 | So we're doing a weight on it? |
| 00:34:01 | Yeah. |
| 00:34:02 | Wait, wait, wait. Hold on. Hold on. Hold on. |
| 00:34:05 | Okay. Which part are you guys stuck on here? |
| 00:34:07 | We don't get the whole thing because- |
| 00:34:08 | I know. |
| 00:34:09 | Resistance force- wait. |
| 00:34:10 | Okay. That's where you just //pick up- pick up the weight. |
| 00:34:11 | //Four and a half pounds. |
| 00:34:12 | It's not pounds. What is it measured in? |
| 00:34:14 | Newtons. |
| 00:34:15 | Newtons. |
| 00:34:16 | Four and a half Newtons. |
| 00:34:20 | Four and a half. |
| 00:34:21 | It's not four and a half. |
| 00:34:22 | It's halfway between four and six. That's not four and a half. |
| 00:34:25 | Oh. Five. |
| 00:34:26 | What are we measuring though on this? |
| 00:34:28 | You're measuring three things. Vincent just did one of them. |
| 00:34:31 | Yeah, but- |
| 00:34:32 | Okay. You- you- you're //sure you have it zeroed before you start it? |
| 00:34:33 | //Well, what is this one- |
| 00:34:36 | I'd ask the same question to Vincent, too. |
| 00:34:37 | Zero? |
| 00:34:38 | When it- when it's not hooked up, is it at zero? No, it's not. |
| 00:34:43 | //Oh. |
| 00:34:44 | //So you want to adjust it so that it is in fact on zero when you start. |
| 00:34:48 | Okay. |
| 00:34:49 | So that's resistance force. Effort force, when the weight is on here- |
| 00:34:54 | It's like Newtons. |
| 00:34:55 | Tie a loop. |
| 00:34:56 | I got four and a half. |
| 00:34:57 | Pull it down. Read what the force is on the scale. |
| 00:35:00 | I don't get what you're saying, "set it to zero." Like, it can't move. |
| 00:35:04 | Okay. This thing goes up and down. |
| 00:35:07 | Oh, I didn't see that. |
| 00:35:08 | Put it so it's on zero. Yeah? |
| 00:35:09 | How do we set it up for that one? |
| 00:35:11 | Okay. |
| 00:35:12 | Do we have to set it up- |
| 00:35:13 | You need to tie it up here. |
| 00:35:14 | Yeah. |
| 00:35:15 | You need a pulley here. |
| 00:35:16 | Uh-huh. |
| 00:35:17 | A weight here. There's a loop of string up here. |
| 00:35:19 | Okay. |
| 00:35:20 | That connects your pulley to your weight. |
| 00:35:22 | Uh-huh. |
| 00:35:23 | The string from the bar goes through the pulley and up. |
| 00:35:25 | Okay. |
| 00:35:26 | Just like it looks in the picture. |
| 00:35:27 | Do you have any tissues? |
| 00:35:28 | Uh, no, but I have paper towels over by Diane there so- I think the tissue box is all empty. |
| 00:35:38 | Okay. What do we do with this? |
| 00:35:40 | That's how- what you measure the forces with. |
| 00:35:43 | So it's this one and that one? |
| 00:35:45 | It's- you're gonna use it to measure //resistance force and effort force. |
| 00:35:48 | //now look, Mr. Melville- |
| 00:35:49 | We got four and a half. |
| 00:35:51 | When I did that, I started out at 50 and I ended up with 60 so //what would I write? |
| 00:35:54 | //Okay. So it would be how many centimeters? |
| 00:35:55 | Ten. |
| 00:35:56 | Ten centimeters, yeah. |
| 00:35:57 | So where do I write that one? On effort distance? |
| 00:36:01 | Effort distance, yes. |
| 00:36:02 | Wait, four Newtons. |
| 00:36:04 | Four Newtons. |
| 00:36:07 | Four and a half. |
| 00:36:08 | We put that on. |
| 00:36:09 | Now, did you have it zeroed before you weighed it? |
| 00:36:11 | Yes. |
| 00:36:13 | Okay. It should be at zero, and you'll see that it's way above the zero. |
| 00:36:16 | Oh. |
| 00:36:17 | You actually just slide this up and down to get it on zero. |
| 00:36:20 | Oh. Okay. |
| 00:36:23 | You're gonna want to get the knots out of that when you're done, too. |
| 00:36:32 | It's not four and a half Newtons. Look. It's almost six. |
| 00:36:35 | It's four and a half. |
| 00:36:36 | It's almost six. Look. Watch. |
| 00:36:37 | You have to make sure it doesn't move. |
| 00:36:39 | Watch. |
| 00:36:41 | That's far away. You're supposed to stay with four. |
| 00:36:42 | Isn't it almost six? |
| 00:36:46 | That's probably way too far. |
| 00:36:48 | Ours is six- |
| 00:36:49 | Mr. Melville? |
| 00:36:50 | Yeah? |
| 00:36:51 | Which one is the effort force? |
| 00:36:52 | How do you do the mechanical advantage? |
| 00:36:53 | You want to take this off, but don't worry about that 'till later. We're gonna do- do it all together. |
| 00:36:57 | All right. |
| 00:36:58 | You want to take this off of here because- yeah. You need the knot out of that, too. |
| 00:37:04 | You- you need this off the weight. You- instead of being looped around here, you need it looped around up here. |
| 00:37:07 | Oh. |
| 00:37:08 | Because it's supported from the top. |
| 00:37:10 | Okay. |
| 00:37:14 | Mechanical advantage. |
| 00:37:17 | How do we find the effort points? |
| 00:37:20 | When your weight is on there, you need a loop here. |
| 00:37:25 | With the weight off the ground, hook the scale up, so that you can read on the scale. |
| 00:37:33 | Okay? |
| 00:37:34 | Audrey, what you working on? |
| 00:37:42 | Audrey, what you working on? |
| 00:37:44 | This. |
| 00:37:45 | Did you help Ian out with //the lab setup? |
| 00:37:47 | //Mr. Melville? |
| 00:37:48 | Yes? |
| 00:37:49 | What do you write for (here)? |
| 00:37:50 | The force- distance and force? |
| 00:37:52 | Effort. |
| 00:37:53 | And effort force? |
| 00:37:55 | Okay. Effort //force- |
| 00:37:56 | //And mechanical average? |
| 00:37:57 | Effort force. Don't worry about mechanical advantage yet. |
| 00:38:01 | For effort force- |
| 00:38:08 | you need to tie a loop here in your string. You need to lift it off the ground- |
| 00:38:13 | You said not to tie anything. |
| 00:38:15 | No, I didn't. I said, "Make sure the knots are gone when you're done." |
| 00:38:18 | Oh. |
| 00:38:19 | I specifically told you to tie a knot here because you're gonna hook this up to it and lift it off the ground and read the effort force. |
| 00:38:25 | That's effort force. The effort distance is how far this moved in lifting this 10 //centimeters off the ground. |
| 00:38:33 | //Okay. I got you. |
| 00:38:34 | So you are gonna have one person measuring that it's 10 centimeters, the other person measuring how far their fingers moved //when they did that. |
| 00:38:39 | //This is for Andrew. |
| 00:38:41 | Thanks. |
| 00:38:42 | I told you. |
| 00:38:44 | You //didn't tell me anything. |
| 00:38:45 | //Mister- Miss Isaac sent him in. |
| 00:38:47 | Miss who? |
| 00:38:48 | Miss Isaac sent him in. |
| 00:38:50 | Oh. It's from Miss Isaac. Okay. |
| 00:38:55 | Do I got two of them? |
| 00:38:57 | No. Just one. |
| 00:38:58 | Just Andrew? |
| 00:38:59 | Yeah. |
| 00:39:00 | You got stuff to work on, dude? |
| 00:39:01 | Yeah. |
| 00:39:02 | Okay. Come here. |
| 00:39:03 | Richard, you're still (inaudible). |
| 00:39:06 | Thanks. You can work right there. That'd be fine. |
| 00:39:11 | Hopefully we'll never have to use this. |
| 00:39:13 | Yes, except when subs are here. |
| 00:39:17 | This counts as a homework stamp, right? |
| 00:39:20 | What's that? |
| 00:39:21 | This counts as a homework stamp, right? |
| 00:39:22 | I have no idea why that's on there. What is that on there? |
| 00:39:25 | Yeah. //I wonder why. |
| 00:39:26 | //Is that the day you couldn't find a blank piece of paper and I stamped that on there for you? |
| 00:39:30 | No. It's- //I don't know (inaudible)- |
| 00:39:31 | //Because there are no more- |
| 00:39:32 | Okay, look at (inaudible). Let's do this. |
| 00:39:34 | Okay, I'm gonna bring it up, //and you measure 10 centimeters off of the table. |
| 00:39:35 | //I don't remember stamping it either. I have no idea what that is. |
| 00:39:38 | Mr. Melville? Mr. Melville? |
| 00:39:39 | Yeah? |
| 00:39:41 | Andrew, you need to sit down. You need to sit down. |
| 00:39:45 | Wait. It's not- |
| 00:39:46 | That's 10 inches, not //centimeters. |
| 00:39:48 | //You guys are seriously gonna want to //get that knot out of there. |
| 00:39:49 | //We need to go inches. |
| 00:39:50 | It really messes up the pulleys. |
| 00:39:53 | Ten centimeters. //Centimeters! |
| 00:39:54 | //No. No. I said you need to tie a loop to measure effort force, but you don't want any knots in the string. It messes up going through the pulley. |
| 00:40:01 | You have to have your finger right here. Let go. |
| 00:40:03 | You mean a loop like this, Mr. Melville? |
| 00:40:05 | What's that? |
| 00:40:06 | Like this? |
| 00:40:07 | Bridget? What are we weighing? |
| 00:40:10 | A loop, that circle thing? |
| 00:40:11 | I don't understand what you're saying. |
| 00:40:12 | Never mind. |
| 00:40:16 | The only time you need a loop in there is when you're measuring the effort force. Other than that, the knot should be out of the string. |
| 00:40:23 | Understand? |
| 00:40:24 | Okay. |
| 00:40:25 | Yes? |
| 00:40:26 | (inaudible) |
| 00:40:27 | That's fine. It has to be enough that you can- well, it should be on the pulley for one. |
| 00:40:31 | Is Savannah here? |
| 00:40:33 | Savannah? |
| 00:40:35 | I wasn't looking at that. I was- |
| 00:40:36 | And then you have to pull down to make the weight go up. No, no, no. |
| 00:40:40 | You want to pull down with the scale so you're actually measuring the force on the- |
| 00:40:44 | So like this? |
| 00:40:45 | No. |
| 00:40:46 | You do it. I don't understand- |
| 00:40:47 | There. There. That's it. Now pull down on the scale. |
| 00:40:50 | On the scale? |
| 00:40:51 | On the scale. Let go of the other string. There you go. That's it. |
| 00:40:56 | But then you would be looking at it- |
| 00:40:58 | Yes. You're gonna be looking at it upside down. |
| 00:41:00 | I was, like, like four and a half. |
| 00:41:01 | I get what you- |
| 00:41:02 | There you go. Yeah. Now, untie it when you're done. |
| 00:41:05 | Four and a half? |
| 00:41:06 | So I go like this, right? |
| 00:41:07 | Where's my pen? |
| 00:41:08 | Yes. But you want to do it straight down, because if you do it at an angle, it gives you a slightly different reading. |
| 00:41:13 | Six Newtons. |
| 00:41:16 | Course. |
| 00:41:18 | Six Newtons. |
| 00:41:19 | Six? |
| 00:41:20 | Yeah. |
| 00:41:22 | Why do you tie that around? |
| 00:41:25 | What do you need to do for this? |
| 00:41:27 | You need to tie your string at the top, attach your weight directly to the pulley with this little loop of string that I put up here. |
| 00:41:36 | And then you need to run your string through the pulley and up, and you'll be lifting in an upward direction for that one. |
| 00:41:44 | You didn't see the pulley. Lift the (rope). |
| 00:41:47 | Yes, ma'am. |
| 00:41:48 | Yes, ma'am? |
| 00:41:49 | I said, "Yes, ma'am." |
| 00:41:50 | Oh. I see. I see. Wait. No. Wait. No. No. Not that. We already pushed that. |
| 00:41:54 | Yes, ma'am? |
| 00:41:55 | Mr. Melville, //my loop isn't very good. |
| 00:41:56 | //(inaudible) and it's 38 centimeters. Where do you put it? I forgot. |
| 00:42:00 | What's 38 centimeters? |
| 00:42:02 | The (inaudible). This. |
| 00:42:03 | No. No, no, no. It's not- it's how far you moved it. |
| 00:42:07 | Yes, I did. |
| 00:42:08 | No. It's how far you moved it in raising it 10 centimeters. So start somewhere even like 50. |
| 00:42:15 | Marcello? Measure the weight. Measure the weight and tell me when it's 10 centimeters off the ground. |
| 00:42:23 | How do you tie a knot? |
| 00:42:24 | There. |
| 00:42:25 | Right there? |
| 00:42:26 | Yeah. |
| 00:42:27 | Okay. I'm at 60 now. Where did I start? |
| 00:42:28 | 50. |
| 00:42:29 | I started at 50 so how far did I pull up? |
| 00:42:30 | Ten centimeters. |
| 00:42:31 | There you go. That's what goes in this first spot. |
| 00:42:34 | The distance that you moved //the effort string. |
| 00:42:36 | //The effort distance? |
| 00:42:37 | The effort distance, yeah. |
| 00:42:39 | Yes? |
| 00:42:40 | We did- we already did this one. How do we do this? |
| 00:42:45 | You're gonna tie- tie your string to the top. Actually, you can just loop it through, around. |
| 00:42:52 | It's gonna go down, through the pulley. The pulley will be attached with this little loop directly to your weight. |
| 00:42:59 | No. |
| 00:43:00 | I don't get it. Can you show me again? |
| 00:43:01 | No. I- look at the picture. I want you to look at the picture and set it up like the picture. |
| 00:43:05 | We finished all those (inaudible)- |
| 00:43:06 | You finished all four of them? |
| 00:43:08 | Not all four- |
| 00:43:09 | or you finished the first and second? |
| 00:43:11 | Can I see your data? |
| 00:43:17 | Is it the last one, Zeb? |
| 00:43:21 | You guys were able to get the first and second ones done? |
| 00:43:25 | Who? Us? |
| 00:43:26 | It's us. |
| 00:43:27 | Oh, it's you guys. |
| 00:43:29 | What did you do? |
| 00:43:32 | Look at this. |
| 00:43:34 | The effort force was 16 Newtons? |
| 00:43:41 | Sixteen... oh, 16 centimeters. |
| 00:43:44 | Okay. That would be effort distance. |
| 00:43:46 | Oh. |
| 00:43:48 | Okay, we can go on. |
| 00:43:49 | Okay. The resistance force, how did the weight get- your weight was three Newtons both times? |
| 00:43:56 | Which weight do you guys have? Oh. You guys have the brown one, right? |
| 00:43:58 | Yeah. |
| 00:43:59 | Okay. So that one's different. |
| 00:44:00 | Okay, the one thing you didn't do then on- on, uh, either of these setups is correctly figure out the effort force. |
| 00:44:09 | That's the one where you tie a knot in the string, |
| 00:44:11 | //Oh yeah, we got to do (this) |
| 00:44:12 | //hook the scale up to it and pull. |
| 00:44:15 | We did it on this one, and we got 12. |
| 00:44:16 | No, you didn't. |
| 00:44:22 | And does that say 16 also? Okay. That one's not right either. |
| 00:44:26 | When you lift this off the ground by 10 centimeters- Miguel, stop it. |
| 00:44:35 | When you lift it off the ground by 10 centimeters, how far did this string move? That's what you need to measure. |
| 00:44:40 | Oh. Okay. |
| 00:44:42 | Okay? I don't think you did it right either place. |
| 00:44:45 | This is hard. We need Will in here. He's a smart boy. |
| 00:44:49 | You took my stool. |
| 00:44:50 | When you get it set up again, call me over. I'll //show you. |
| 00:44:53 | //All right. |
| 00:44:55 | Yeah? |
| 00:44:56 | Can you help us with part two? |
| 00:44:57 | Yeah. |
| 00:44:58 | Okay. Whatcha stuck on? |
| 00:45:00 | We don't know how to do this thing. We're not- |
| 00:45:01 | Okay. Well, look at it. Your string should be tied to the top bar. Do you see that in the picture? |
| 00:45:10 | Well, you- you can loop it through just like you- |
| 00:45:14 | Oh no, well look. |
| 00:45:17 | Here, I'll give you one hint. Hand me the other end. |
| 00:45:25 | Oh, (it will) slide through. |
| 00:45:26 | Oh. |
| 00:45:33 | It's the same. |
| 00:45:38 | Then you hook the pulley directly up to the weight like it shows, run the string through the pulley. |
| 00:45:43 | That little loop of string- yeah. That's how you do that part. Ian, you gonna do anything today? |
| 00:45:48 | I already- |
| 00:45:49 | I already did one. |
| 00:45:51 | I did practically everything. |
| 00:45:54 | //Oh, thank you. |
| 00:45:55 | //How do you do this part? |
| 00:45:56 | Can I actually look at it where I can see it. |
| 00:45:57 | How do you do mechanical advantage? |
| 00:46:00 | We're gonna do that one together. What //was- |
| 00:46:02 | //(We got) 25. |
| 00:46:03 | What was 25? |
| 00:46:04 | That's what I told her. |
| 00:46:05 | Where does it say 25? |
| 00:46:07 | On 23 or whatever that says. What is that? |
| 00:46:10 | That says 23. |
| 00:46:11 | So where did that come from? Did //you just make that up? |
| 00:46:12 | //You take 12, six- oh, wait. I forgot to add 10, huh? Okay. It's- it's 33. |
| 00:46:17 | Why? |
| 00:46:18 | Because I added it all up. |
| 00:46:20 | Why? |
| 00:46:21 | Watch out. |
| 00:46:22 | Why not? |
| 00:46:23 | Oh, so for this one we have to do- |
| 00:46:24 | Why? |
| 00:46:25 | I don't know. |
| 00:46:26 | It doesn't make any sense. |
| 00:46:27 | Well, I don't know how else to do it. That's why. |
| 00:46:29 | How do you do this part? The one where you put that- |
| 00:46:33 | You broke it. |
| 00:46:35 | No, I didn't. |
| 00:46:36 | That's your effort force. You just pull that one down. |
| 00:46:38 | This? |
| 00:46:39 | Yep. |
| 00:46:40 | Look it, Mr. Melville. We did it. |
| 00:46:41 | Don, that's it. Perfect. Excellent job. |
| 00:46:43 | Okay, folks. It's time to clean up. |
| 00:46:46 | You get out of here when your stations look exactly like they did when you came //to the station, |
| 00:46:51 | //Hurry up, hurry up, hurry up. |
| 00:46:53 | So everything hung back neatly where it belongs. |
| 00:46:57 | That was like this. |
| 00:46:58 | And, uh- oh, can I have that (inaudible)? |
| 00:47:01 | //After school. |
| 00:47:02 | //Mr. Melville- |
| 00:47:07 | You think someone can pick up our notebook? |
| 00:47:09 | You're scaring me, Rosalie. |
| 00:47:11 | Uh, Diane dropped her pencil down the drain. |
| 00:47:14 | You did? Seriously? I have no way of getting it out. |
| 00:47:18 | No one- |
| 00:47:19 | It goes down- it goes down about six inches before- |
| 00:47:21 | No one must see that book. Nobody. |
| 00:47:24 | How about I read the whole thing between now and sixth- |
| 00:47:27 | Don't do it. |
| 00:47:29 | Just to remember. You come after school and you can have it. |
| 00:47:30 | Okay. |
| 00:47:31 | Yes? |
| 00:47:32 | Um, what we're doing is we're trying to find the, um- |
| 00:47:35 | //That looks perfect. |
| 00:47:36 | //resistance from the lift, //10 centimeters? |
| 00:47:37 | //Yes. |
| 00:47:38 | But how do you calculate the effort force? |
| 00:47:40 | Tie a knot in the string. Hook the scale through it and pull. Read what you get on the scale. |
| 00:47:46 | Oh. Okay. And- and we weigh- we already weighed it. It weighs five and a half Newtons. |
| 00:47:50 | That's what- that's the force the gravity is pulling downward with. |
| 00:47:53 | So resist- |
| 00:47:54 | That's correct. That's the resistance force. |
| 00:47:55 | And after that we just cut- |
| 00:47:57 | No. Don't worry about that yet. We're gonna do that together. |
| 00:47:59 | Okay. And it's the same thing here if we were to do it? |
| 00:48:02 | Exactly. It's just a different pulley setup, but the calculations are the same. |
| 00:48:06 | Oh. Okay. |
| 00:48:09 | I thought I told you guys that yesterday. |
| 00:48:11 | You said Friday. |
| 00:48:12 | Right. Tomorrow's Friday. That's cool. |
| 00:48:17 | Folks, seriously, your stations need disassembled, cleaned up, put back the way they were. |
| 00:48:23 | I don't see a single station that's acceptable right now. |
| 00:48:27 | That one is. |
| 00:48:28 | Look at ours. |
| 00:48:29 | Ours. |
| 00:48:32 | You guys don't get to go until the station looks like it did when you got there. |
| 00:48:39 | Are you serious? |
| 00:48:40 | Serious. |
| 00:48:41 | That's how it looked when I got there. |
| 00:48:42 | That looks good. |
| 00:48:43 | I know, huh. |
| 00:48:46 | Everything neatly hung up on those corners like it was when you got there. |
| 00:48:51 | Rulers lined up neatly on the table. No knots in the string. Please get them cleaned up. |
| 00:49:03 | We couldn't get the pencil out of the drain. |
| 00:49:05 | No. You won't probably be able to. I'm sure there's probably many, many things down the drain. |
| 00:49:13 | You probably wouldn't want your pencil back after it'd been down the drain anyways. It's kind of nasty. |
| 00:49:18 | Does this go in the closet? |
| 00:49:23 | (Would you) get my pencil out? |
| 00:49:24 | No. |
| 00:49:26 | I think it went all the way down the drain, because it's not in there no more, Diane. |
| 00:49:31 | There's a- there's a drain trap so it can't go past. |
| 00:49:35 | Well, what if we took off that sink part and like- |
| 00:49:38 | Well, we could. You just need a screwdriver and, uh, you need some pipe tape so when you put it back so that it seals again, |
| 00:49:49 | and you could rescal- rescue her mangy old pencil. |
| 00:49:53 | You need it desperately? |
| 00:49:54 | Uh-huh. |
| 00:49:55 | Yes? |
| 00:49:58 | Excuse me, //Mr. Melville? |
| 00:49:59 | //Hey, folks. Let's stand up and get your chairs pushed under, please. |
| 00:50:22 | Shh. |
| 00:50:24 | (inaudible) |
| 00:50:25 | Just push it under, but you don't get to go until anybody else goes. Okay, Andrew? |
| 00:50:32 | Punch and munch tomorrow, not punch and munch and movie. Just punch and munch. You do have a quiz tomorrow. |
| 00:50:37 | You might want to look over some of the stuff we've talked about this week like work and machines- |
| 00:50:43 | What can we bring again? |
| 00:50:44 | Anything except for gum, corn nuts, sunflower seeds and chips. Anything else is fair game. |
| 00:50:48 | All right. I need Miguel, Matt, Ian, and Audrey. They owe me two minutes. The rest of you may go. |
| 00:50:53 | What did I do- |
| 00:50:54 | Miguel, you owe me 15 minutes at lunch, tomorrow. |
| 00:50:57 | Expect to see you then. |
| 00:51:00 | What did I do to get that- |