***AP Physics 1 Thread 2014-2015***

@boji98 is there a reason why?

@boji98 Oops, sorry

Where should I look for the FRQ?

https://secure-media.collegeboard.org/digitalServices/pdf/ap/ap15_frq_physics_1.pdf

1 a. (m2-m1)g/(m1+m2)…???
1b. does not change

No it’s only divided by m2 because it’s the acceleration of block 2. @yoyo27

it cant be because of the total mass of the sytem is m1+m2…

When you calculate acceleration of one aspect of a system you divide it by the mass of only the object. That’s what the question is asking for, not the entire system. Close, but no cigar @yoyo27

@yoyo27 it gets smaller, just use the equation you derived

@aao1997 the acceleration for both blocks is the same since they both experience the same tension.

No it doesn’t…he’s right about that part. You have to separate you vertical and horizontal force thinking. There’s no friction so the vertical affecting the horizontal via pulley is negligible, or, nonexistent. Thus no change. @mayman

Yes but the question is asking for block 2 and you need to derive a different equation for block two. I just worked through this with my teachwr

apparently the equation I derived is wrong???
no it doesnt , bcause the mass exerts no force on the sytsem because it is counteracted by th force of the table if i am wrong inform me cuz then my first part was right lol… pls inform me

Your second part is correct, first is wrong. You just need to answer what the question is asking for.

I said the acceleration decreases due to the third block because, though the third block doesn’t change the force of the system, it increases the mass, thus decreasing the acceleration of the system (and block 2).

i dont understand why the acceleration of m2 doesnt egual the accel of the system literally every pulley problem is set equal to sigma ma which means the total mass of the two blocks is m meaning for part a you have to divide by m1+m2

Everyone I asked said the acceleration decreases :confused:

@mayman I’m pretty sure that’s correct

@yoyo27 THE ACCELERATIONS ARE EQUAL. But you express block two’s travel differently than you do block one’s.

Differently from the system, too.