AP Physics C 2017 Mechanics Free Response Solutions

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[planetpeter]

Just wanted to thank you Dan for all these videos. I got a 5 this year by self-studying your videos!

[deemd]

Self-studied this and got a 5! Thanks for your vids... taking E&M next year!

[swiftyedits]

i have SOME assurance i may still get that 5, thanks dan!! A lot more simple kinematics and a lot more derivation on a frq than normal, but i'm into that stuff so i liked this year's frqs

[dalenassar]

I just started the video (paused) to say GREAT response--I am also no fan of being told how to carry out the solution--it defeats a very important purpose of problem-solving. A BIG deal--THANKS!!

[abdelrahmansobhy]

in Q3 b
why we didn't consider the potential energy at the table and apply conservation from the table to the floor?
so, mgh + 2.5 = 1/2 mv^2 +1/2 I w^2

[tarunrajg.mohanraj]

For 3b, why is the total kinetic energy on the floor equal to 2.45 J? Isn't that the kinetic energy when on the table (which we found in part a)? Since there's a change in potential energy between the table and the floor, shouldn't the kinetic energy also be changing? In part c, on the other hand, you do use 6.25 J as the total kinetic energy on the floor...why is this different from the value in part b?

[prodsegi]

For the last question, why is there no rotational kinetic energy when the cylinder is on the ramp?

[josephghobrial]

The official free response has the same answer for 3a. But it seems to me there is a mistake. The KE at the bottom should not be 2.5J, it should have gained energy because of the extra loss in potential energy. To put in another way, it should have gained more speed at the bottom than at the table level because of the extra time under acceleration of gravity.

[dreamerchef]

Do you have tutorial lesson videos about pressure, Newton's Laws, molarity???

[jakobjohnson]

For question 1 part g, do you think credit would be awarded if I said that the disparity between the acceleration of gravity measured in the two experiments could be attributed to the pulley in the first experiment slipping while in the second experiment it did not slip when released? Thanks for the videos!

[xtradv]

I was wondering why does the kinetic energy in question 3b not change from the table to the floor? If there is a change in the potential energy from gravity (from the table to the floor) why doesn't this correspond to a change in the kinetic energy as well? Thank you for any reply.

[SOrl]

When are the other physics videos coming out?

[thesandman]

should we expect the physics 1 answers next? thanks for putting the effort into this!

[shaunwu]

On 3e ii., because the sphere rotates faster due to its less inertia, it should have a greater angular velocity and thus, a greater rotational kinetic energy than the cylinder which has a greater inertia. But the answer said the rotational energy of the sphere is less than the rotational energy of cylinder. Can you explain to me why my reasoning is wrong? Thank you!

[redkingizaya]

I had the other version the one with two springs and a conversation of energy problem. Are those questions also gonna be released?

[Noelaseung]

For number 2 part d, why is Bv^2 the only force used to find the speed of the block? Also, thank you so much for the videos!

[mahabubulalam]

I have 20 days before the AP Exam for Mechanics. I didn’t learn anything whole year. Do u think it’s possible to self study from your videos and learn everything I need to know to get a 4 on the AP Exam. I took AP Calc already so I know Calculus.

[twinamoto]

When will you upload the answers for the AP Physics 1 2017 free response questions?? I really want to know how your answers compare to mine. My AP Physics teacher recommended your channel to look at the answers

[proexcel]

Hello Dan! Firstly, I would like to thank you for making such and amazing video. But I would like to check for 10:48, shouldn't it sqrt(2gh/2) = (1/sqrt(2))sqrt(2gh)? Instead of (1/4)sqrt(2gh).

[JaffreyH]

How do we know what correctly goes for x and y-axis?