AP Physics C: Post-exam FRQ solutions (Mech and E&M)

[ChemE14]

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@student1992

1.for mech 1, do i get any credit if i just plotted vt against time instead of vt^2 against time? (i just used the data given as it is) i included the best-fit line as well.

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<p>You may lose 1 - 2 points for not vlotting v_t^2 versus time. I’m basing this estimate on 2006 #2c.</p>

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@student1992

2. for mech 2, i got the 3rd q wrong (i equated mgh = 1/2 Iw^2 instead of mgh = 1/2 mv^2 + 1/2 Iw^2…apparently forgot to include translational KE…), consequently leading to a wrong answer for the last q (finding the total distance). If my working was all correct except for the incorrect value of velocity from the 3rd q, will i be able to get credit, if any, for the last q?

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<p>Well, first off, the last part is asking for final velocity of the ball plus box plus wagon. Assuming you did find the final velocity, you will get 100% credit if everything else is right for part d. You could end up getting no credit for part c because by not including KE_translational you’re basically saying the center of mass is not moving.</p>