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# M1 Pulley question Watch

1. Everything's smooth, inextensible & light, so no friction or any other funny business. The system is released from rest.

I have to:
a) Find the common magnitude of the accelerations of the blocks
b) Find the tensions in the strings

How do I do it?
2. Have you drawn a picture with the weights and tensions?
3. Treat each block as an individual system and then use F=ma
4. (Original post by najinaji)

Everything's smooth, inextensible & light, so no friction or any other funny business. The system is released from rest.

I have to:
a) Find the common magnitude of the accelerations of the blocks
b) Find the tensions in the strings

How do I do it?
Let the Tension in the string joining A and P be T, and the tension in the string joining P and B be S. Since the mass of B is greater than the mass of A, the block P will move to the right, let a be the acceleration of the system.

0.5g-S=0.5a (considering the motion of block B)
T-0.3g=0.3a (considering the motion of block A)
S-T=0.6a (considering the motion of block P)

5. (Original post by Aurum)
Let the Tension in the string joining A and P be T, and the tension in the string joining P and B be S. Since the mass of B is greater than the mass of A, the block P will move to the right, let a be the acceleration of the system.

0.5g-S=0.5a (considering the motion of block B)
T-0.3g=0.3a (considering the motion of block A)
S-T=0.6a (considering the motion of block P)
Ah, I see. Thank you. I kept doing 0.5g + 0.3g rather than minus.

Updated: May 6, 2012
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