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- [Voiceover] All right, part d.

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Explain how any correct aspects

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of the student's reasoning
identified in part b

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are expressed by your mathematical
relationships in part c,

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and explain how your
relationship in part c correct,

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how your relationships in part c

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correct any incorrect aspects
of the student's reasoning

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identified in part b.

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It's a bit of a mouthful,

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but they're just saying,

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"Hey, kinda connect the
dots between part c"

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"and the two parts of part b."

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Refer to the relationships
you wrote in part c,

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not just the final answer you obtained

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by manipulating those relationships.

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And so we can,

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let me write it down here.

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So d.

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So part c

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shows us

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that doubling,

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doubling compression

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does result in more potential energy.

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Doubling compression does result

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in more,

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in more energy.

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And you could clarify that this is,

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this is potential,

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potential and kinetic

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at different points in time.

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And then we could even draw a line to it.

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So we see that,

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we see that right over here.

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That is, that is these,

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that line,

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and then that line right
over there shows that.

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So I could draw a bit of an arrow to it.

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They want us to reference
some of what we saw before.

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And just to make it clear,

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I can put in parentheses.

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I can show that U two
is equal to four U one,

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and that K two is equal to four,

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four K one.

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However, however,

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however,

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since the kinetic energy,

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since the kinetic

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energy

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is four times greater,

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and you have

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the same, same force of friction,

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force of friction,

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the distance is going to
be four times as long.

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The stopping distance,

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distance,

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is going to be four times as much.

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Is going to be

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four times as long.

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And even when we,

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so the correct parts.

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Part c shows us that
doubling the compression

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does result in more energy.

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And I could add and
more stopping distance.

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Let me do it there.

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And more stopping,

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stopping distance.

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Whoops.

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And more stopping distance.

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And the stopping distance,

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that arrow is easier to draw.

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And more stopping distance.

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However, since the kinetic
energy is four times greater,

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and you have the same force of friction,

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the stopping distance is going to be

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four times as long.

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And we saw that as well over there.

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So we're saying hey look,

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the student was right

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that more compression is more energy,

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more stopping distance.

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However, it's going to
be four times as long,

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the stopping distance,

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not two times

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as,

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not two times as far.

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And there you go.