Question

In the figure it is shown that the velocity of lift is $2m{s}^{-1}$ while string is winding on the motor shaft with velocity $2m{s}^{-1}$ and shaft A is moving downward with velocity $2m{s}^{-1}$ with respect to lift, then find out the velocity of block B.

• A. $2m{s}^{-1}$
• B. $3m{s}^{-1}$
• C. $4m{s}^{-1}$
• D. None of these

Answer 1

The correct option is D None of these

If we considered whole situation with respect to the lift then we can see that block B has velocity in both direction of equal value = 2m/s so block B is not moving while shaft A has velocity in downward direction.

$V_b=0V_a=2m/s$