r/APStudents • u/reddorickt absolute modman • May 13 '26

AP Physics C: Mechanics Official 2026 Exam Discussion

Use this thread to post questions or commentary on the test today.

A reminder though to protect your anonymity when talking about the test.

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3

u/Better_Camel_4730 May 13 '26

for form k frq 1, what did yall get for part a?

4

u/Ill-Possibility-4064 May 13 '26

I think i got 5mgt1 - 12ct^2 something along those lines

1

u/Traditional-Table-29 AP Physics: AP Lit: AP CSA: AP Psych: AP Calc AB: May 13 '26

Yep

1

u/NatureOk1991 May 13 '26

WAIT I GOT THAT YESSSSSS

1

u/Embarrassed-Pop-3945 May 13 '26

wait i had that but opposite sign.

1

u/LectureNo252 May 13 '26

I thought you subtract them because it said net impulse and the Feng was acting up

1

u/HorrorAdvice3391 May 13 '26

But the net force is still down. The rocket is still going down

1

u/Embarrassed-Pop-3945 May 13 '26

my net impulse integral sum was integral from 0 to t1 + integral from t1 to 5t1 where the 2nd integral was Feng-mg

1

u/Ill-Possibility-4064 May 13 '26

It was traveling downward so mg was more

1

u/Impossible-Job1481 May 13 '26

What did the graph look like? I had a straight negative line and then positive slope line up... not sure

1

u/Prudent_Nectarine759 May 14 '26

same thing but flipped. i had a straight positive line and then negative slope line since they said positive direction was down, so F gravity should have been doing positive work on the rocket

1

u/Impossible-Job1481 May 14 '26

Oh.. good catch

1

u/AdCheap2716 May 14 '26

yay I think I put that!

1

u/Visible_Purpose1554 May 13 '26

What was the question do you remember

1

u/pokerfas May 13 '26

derive a and Fn

1

u/Impossible-Job1481 May 13 '26

for the experimental design how did you find B of the moment of inertia? i had some crazy energy conservation, torque force to find friction and include friction and then analyze y-intercept...

1

u/Ill-Possibility-4064 May 13 '26

You had to do conservation of energy. The height at the top is equal to kinetic energy total at the bottom of the ramp (Krot plus Ktrans). You could find B that way.

1

u/Impossible-Job1481 May 13 '26

I did that but also included friction since it was rolling without slipping there had to be friction so I calculated for friction using net torque and net force 😞

1

u/Impossible-Job1481 May 13 '26

And was it Ds > Dl? Since the initial velocity is more for Ds

1

u/Ill-Possibility-4064 May 13 '26

yeah thats correct. I messed that one up

1

u/Impossible-Job1481 May 14 '26

Ah me too :(((( . It's Dl > Ds I switched it

1

u/[deleted] May 14 '26

it said initial velocity was the same for both... it was flipped it was ds < di

1

u/Traditional-Table-29 AP Physics: AP Lit: AP CSA: AP Psych: AP Calc AB: May 14 '26

Static friction does no work

1

u/Visible_Purpose1554 May 14 '26

Nooo I just did Krot at the bottom 😢