Pully Problem, Force/Tension

[koomba]

Ok I've been working on this problem for a while, and I'm kinda new to physics, so bear with me. So here it is:

Heres the picture of the problem:

http://capa.etsu.edu/msuphysicslib/Graphics/Gtype09/prob68_Atwood1.gif


A frictionless pulley with zero mass is attached to the ceiling, in a gravity field of 9.81 m/s2. Mass M2=0.150 kg is being accelerated downward with a=1.10 m/s2. Calculate the mass m1.

Just assume there is no compression/stretching of the rope on this problem. ALso, I guess the acceleration of M1 would be -1.10 m/s^2, correct? Beyond this I'm really confused. Any help would be greatly appreciated! Thanks.

Steven

[CharlesP]

I suspect a/g = (M2- M1) / (M2 + M1). Then (M2 + M1) a/g = M2 - M1 . and
M1 a/g + M1 = M2 -M2 a/g so M1 = M2 (1-a/g)/(1+a/g) .

[koomba]

I'll see what kind of numbers I get with that, thanks!

Edit: Hey looks like that worked out, thanks man! :biggrin: