Question

The mass of block B is twice the mass of block A, while the mass of the pulley is equal to the mass of block A. The blocks are let free to move and the cord moves on the pulley without slipping or stretching. There is no friction in the pulley axle, and the cord's weight can be ignored.What happens when block B moves downward?

A) The Left cord pulls on the pulley with greater force than the right cord
B)The left and right cord pull with equal force on the pulley
C)the right cord pulls on the pulley with greater force than the left cord

Answer 1

C)the right cord pulls on the pulley with greater force than the left cord

Step-by-step explanation:

As we can see the figure that B is connected to the right string while A is connected to the left string

Now force equation for B as it will move downwards is given as

`(2m)g - T_B = (2m)a`

similarly for block A which will move upwards we can write the equation as

`T_A - mg = ma`

now we know that pulley is also rotating so the tangential acceleration of the rope at the contact point with pulley must be same as that of acceleration of the blocks

so here pulley will rotate clockwise direction

So tension in the right string must be more than the left string

So correct answer will be

C)the right cord pulls on the pulley with greater force than the left cord