Energy_Lesson

Excerpt from the Energy Lesson

Students also see a real life example of the situation in the transparency.

MR = teacher

MR:

Let's take a look at this situation here 11:11 Now, we have two carts, or the same cart in two situations. The first question is, which goes farther on the plane, I mean on the plane area not on the incline, but on the flat 11:12, and explain why? (4) OK, this one is Jennifer, no Sylvia

Sylv:

well B, because it get's to go down further and faster

MR:

so you say B, because it goes down farther, and (.) that's why it goes down further (.) Jennifer?

Jenn:

I also think B because it has like more of a start, it can go faster, because it's got more like of a start, (.) faster start

MR:

OK, some others, there where some others, Amanda?

Aman:

I think B because it can go up higher, so it will come down faster

MR:

OK, it's higher. Now the question is, you said it will be B, the question is (.) why? (1) It's the why, what makes this situation (1) but gives that situation something to the car that actually goes down farther? Jenni?

Jenni:

I think B, 11:13 because ahm it's lifted up farther, and if it's lifted up farther it can go down faster and further.

MR:

but what does it have, what does the car have that makes it go down farther, first Kian

Kian:

well, it has less friction, because when it's lower, it just goes, and it goes just like a little bit, 'cause it didn't have very much far. It's got le.., less friction

MR:

so you got something there, Aslam

Asl:

I think B, because the gravity pulls it down to the bottom

MR:

OK, B, because gravity is pulling it down, that is what everyone says. And you say, (.) there is something else. Ahm, go ahead, Ian

Ian:

I'd say B, because when it goes down, it goes the same distance as how high it is.

MR:

OK, so you say, what is the height, what does that height give you, give that car ((Pointing))

Jenni:

it has wheels so that it can go down faster 11:14

MR:

it goes fas...., we still don't know why exactly it goes further? Sylvia?

Sylv:

because when it is going down, and it's so high up it picks up more speed when it's going down

MR:

it picks up more speed, so there is something in that car that gives it more, go ahead, //AJ]

AJ:

I] think, I think, A

MR:

it goes farther, A? Can you try to reason, because you are in opposition to about 15 other people

AJ:

it is closer to the ground

MR:

because it is closer you think it will go farther?

AJ:

plus B, it's, it's, I don't know, about B, B might go faster, but it won't be just at time, A is closer, but it's slower to just start, well it's hard to explain.

MR:

I was wondering, Ian, do you have the car with you?

Ian:

no

MR:

what did you do, Aslam, to get your car with the elastic. Does anyone have a car here? Scott, 11:15, can you, or Bella, can you give me your car please? ((getting it from Bella)) (8) (whispering as Bella brings the car) Bella has this car, where is the elastic?

Bell:

(3) ((brings elastic))

MR:

I wanted to make it go. Can I have another car, please, Scott, is yours

Scot:

there is no elastic

Xs:

no elastic

MR:

no elastic, who has a car with an elastic?

Sham:

me

MR:

does it work?

Sham:

//yeah, ]

Carl:

we have]

MR:

may I have it please?

Sham:

in about a minute

Carl:

we have (our cart?)

MR:

can you give it to us please (3)

Asl:

Dr. Roth

MR:

yeah?

Asl:

I have a different thing

MR:

OK (1) no elastic?

Carl:

someone stole //it]

Kian:

I ] have an elastic

JenF:

I could give you an elastic if you need it

MR:

can you, (2) can I have the cart please ,

Carl:

there is no elastic

MR:

I have an elastic (3) OK, 11:16 (6) May I have your attention again, if we wanted to go, if we let the car, if we let that cart go here, and then let go here, which, (1) will it go farther the first time, or the second time here, (1) ahm, let's have, Laura

Laur:

the second time

MR:

why would it be the second time? What is different?

Laur:

because it stretched farther backward

MR:

but what does that farther stretching do?

Chris:

pushing it harder (.)

MR:

go ahead

Laura:

it gives it more power

MR:

more power, it has (.) you say power, Leanne

Lean:

that's what I was gonna say

MR:

AJ?

AJ:

it has more tension on the elastic

MR:

Ahm (.) which

Asl:

it has more like, it has more strength to pull the thing forward

MR:

OK, Laura said power, .) ahm, is there, is there another 11:17 (2) there are lots of good ideas that I see here, so there is something, when that elastic is stretched it can give more of something to that car. The same here, if it is further up here, it can give more of something, and the cart will go farther. let's then take ah, why does it go farther, we have looked at that. What do you think, what do you think how many times will it go farther, one is here, on the back wheel, here, and the other one is here. AH, Riley?

Ril:

it will go::: 20 cm farthser

MR:

why would you say //20 cm?]

Ril:

B will] go, because it's higher and it'll get more power

MR:

OK,

JenF:

I agree with Riley that it will go 20 cm farther, because it's 20 cm higher than the other one

MR:

Ok, Laura 11:18

Laur:

I think it will go twice as far because it's twice as high

MR:

OK, so ahm, are there other people who agree or disagree with Laura? Aslam?

Asl:

I agree with Laura, because it's twice as far, so

MR:

it's it's twice as high here, or twice as

Asl:

yeah

MR:

Shamir

Sham:

if, if, the, number of the letter A, if it had a heavier weight=

MR:

=no they are both the same, we want to keep that the same, so that we can compare this situation with this situation

Sham:

so then B will go farther because it's higher up=

MR:

=but how many times?

Xf:

20 (1)

Sham:

whatever that distance is, double that

MR:

double that, OK, so you agree with

AJ:

Aslam

MR:

Aslam and Laura that it should go about twice as far. Let's see, remember last time we had that experiment (2) with the inclined plane, and we pulled up that cart like this, OK, we pulled it to here, this is about half, 11:19 and this is B, yeah, this is A, and this is B. What do you think, how much (.5) work does it take to go to here,

MR:	Let's take a look at this situation here 11:11 Now, we have two carts, or the same cart in two situations. The first question is, which goes farther on the plane, I mean on the plane area not on the incline, but on the flat 11:12, and explain why? (4) OK, this one is Jennifer, no Sylvia
Sylv:	well B, because it get's to go down further and faster
MR:	so you say B, because it goes down farther, and (.) that's why it goes down further (.) Jennifer?
Jenn:	I also think B because it has like more of a start, it can go faster, because it's got more like of a start, (.) faster start
MR:	OK, some others, there where some others, Amanda?
Aman:	I think B because it can go up higher, so it will come down faster
MR:	OK, it's higher. Now the question is, you said it will be B, the question is (.) why? (1) It's the why, what makes this situation (1) but gives that situation something to the car that actually goes down farther? Jenni?
Jenni:	I think B, 11:13 because ahm it's lifted up farther, and if it's lifted up farther it can go down faster and further.
MR:	but what does it have, what does the car have that makes it go down farther, first Kian
Kian:	well, it has less friction, because when it's lower, it just goes, and it goes just like a little bit, 'cause it didn't have very much far. It's got le.., less friction
MR:	so you got something there, Aslam
Asl:	I think B, because the gravity pulls it down to the bottom
MR:	OK, B, because gravity is pulling it down, that is what everyone says. And you say, (.) there is something else. Ahm, go ahead, Ian
Ian:	I'd say B, because when it goes down, it goes the same distance as how high it is.
MR:	OK, so you say, what is the height, what does that height give you, give that car ((Pointing))
Jenni:	it has wheels so that it can go down faster 11:14
MR:	it goes fas...., we still don't know why exactly it goes further? Sylvia?
Sylv:	because when it is going down, and it's so high up it picks up more speed when it's going down
MR:	it picks up more speed, so there is something in that car that gives it more, go ahead, //AJ]
AJ:	I] think, I think, A
MR:	it goes farther, A? Can you try to reason, because you are in opposition to about 15 other people
AJ:	it is closer to the ground
MR:	because it is closer you think it will go farther?
AJ:	plus B, it's, it's, I don't know, about B, B might go faster, but it won't be just at time, A is closer, but it's slower to just start, well it's hard to explain.
MR:	I was wondering, Ian, do you have the car with you?
Ian:	no
MR:	what did you do, Aslam, to get your car with the elastic. Does anyone have a car here? Scott, 11:15, can you, or Bella, can you give me your car please? ((getting it from Bella)) (8) (whispering as Bella brings the car) Bella has this car, where is the elastic?
Bell:	(3) ((brings elastic))
MR:	I wanted to make it go. Can I have another car, please, Scott, is yours
Scot:	there is no elastic
Xs:	no elastic
MR:	no elastic, who has a car with an elastic?
Sham:	me
MR:	does it work?
Sham:	//yeah, ]
Carl:	we have]
MR:	may I have it please?
Sham:	in about a minute
Carl:	we have (our cart?)
MR:	can you give it to us please (3)
Asl:	Dr. Roth
MR:	yeah?
Asl:	I have a different thing
MR:	OK (1) no elastic?
Carl:	someone stole //it]
Kian:	I ] have an elastic
JenF:	I could give you an elastic if you need it
MR:	can you, (2) can I have the cart please ,
Carl:	there is no elastic
MR:	I have an elastic (3) OK, 11:16 (6) May I have your attention again, if we wanted to go, if we let the car, if we let that cart go here, and then let go here, which, (1) will it go farther the first time, or the second time here, (1) ahm, let's have, Laura

Laur:	the second time
MR:	why would it be the second time? What is different?
Laur:	because it stretched farther backward
MR:	but what does that farther stretching do?
Chris:	pushing it harder (.)
MR:	go ahead
Laura:	it gives it more power
MR:	more power, it has (.) you say power, Leanne
Lean:	that's what I was gonna say
MR:	AJ?
AJ:	it has more tension on the elastic
MR:	Ahm (.) which
Asl:	it has more like, it has more strength to pull the thing forward
MR:	OK, Laura said power, .) ahm, is there, is there another 11:17 (2) there are lots of good ideas that I see here, so there is something, when that elastic is stretched it can give more of something to that car. The same here, if it is further up here, it can give more of something, and the cart will go farther. let's then take ah, why does it go farther, we have looked at that. What do you think, what do you think how many times will it go farther, one is here, on the back wheel, here, and the other one is here. AH, Riley?
Ril:	it will go::: 20 cm farthser
MR:	why would you say //20 cm?]
Ril:	B will] go, because it's higher and it'll get more power
MR:	OK,
JenF:	I agree with Riley that it will go 20 cm farther, because it's 20 cm higher than the other one
MR:	Ok, Laura 11:18
Laur:	I think it will go twice as far because it's twice as high
MR:	OK, so ahm, are there other people who agree or disagree with Laura? Aslam?
Asl:	I agree with Laura, because it's twice as far, so
MR:	it's it's twice as high here, or twice as
Asl:	yeah
MR:	Shamir
Sham:	if, if, the, number of the letter A, if it had a heavier weight=
MR:	=no they are both the same, we want to keep that the same, so that we can compare this situation with this situation
Sham:	so then B will go farther because it's higher up=
MR:	=but how many times?
Xf:	20 (1)
Sham:	whatever that distance is, double that
MR:	double that, OK, so you agree with
AJ:	Aslam
MR:	Aslam and Laura that it should go about twice as far. Let's see, remember last time we had that experiment (2) with the inclined plane, and we pulled up that cart like this, OK, we pulled it to here, this is about half, 11:19 and this is B, yeah, this is A, and this is B. What do you think, how much (.5) work does it take to go to here,