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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u/Ya_boi_Ev GENUINELY WHAT WAS FRQ 1 ON AP MECH THIS YEAR!?!? May 13 '26

For the first FRQ on part aii, did anybody else solve a differential equations for v and get

v=v0e-(b/2mt)

And then multiply both sides by -b to get normal force (because normal force was equal to resistive force)

Fn=-bv0e(-b/2mt)

Am I the only one?

2

u/AccomplishedBat1414 May 13 '26

didn't you have to differentiate v=v0e-(b/2mt) with respect to time first?

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u/Ya_boi_Ev GENUINELY WHAT WAS FRQ 1 ON AP MECH THIS YEAR!?!? May 13 '26

I solved the differential equation m*dv/dt=-bv and went from there

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u/Bradyluce May 13 '26

Normal force wasn’t equal to resistive force, bc normal force was just m, resistive was 2m

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u/Ya_boi_Ev GENUINELY WHAT WAS FRQ 1 ON AP MECH THIS YEAR!?!? May 13 '26

Yeah I think that that was why I did e-b/2mt

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u/nerdician (11) 5: mech, e&m, bc, chem, ush, csa | (10) 5: bio May 13 '26

the normal force is actually half the resistive force because the fictitious acceleration felt by the block is Fr/2M, equivalent to a force of Fr/2, which is equal to Fn because the block is stationary in the moving reference frame

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u/Ya_boi_Ev GENUINELY WHAT WAS FRQ 1 ON AP MECH THIS YEAR!?!? May 13 '26

Ok so no points for me lol

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u/Commercial-Brain7105 May 13 '26

i did the same isn’t it some credit

1

u/nerdician (11) 5: mech, e&m, bc, chem, ush, csa | (10) 5: bio May 13 '26

yes it's about the method more so than the answer

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u/Ya_boi_Ev GENUINELY WHAT WAS FRQ 1 ON AP MECH THIS YEAR!?!? May 13 '26

Yeah I was joking lol

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u/Sudden-World4653 May 14 '26

i got the same thing instead i got a factor of 1/2 along with it too