Question

The pulley arrangements of figures (a) and (b) are identical. The mass of the rope is negligible. In Fig. (a), the mass m is lifted up by attaching a mass 2m to the other end of the rope. In Fig. (b) , m is lifted up by pulling the other end of the rope with a constant downward force F=2mg. The acceleration of m is the same in both cases.

• A. True
• B. False
• C. True if m < 1 kg
• D. Insufficient data

Answer 1

The correct option is B

False

In the first case, acceleration, $a=\frac{(2m-m)g}{m+2m}=\frac{g}{3}$
In the second case, acceleration, $a^{\prime }=\frac{F-mg}{m}=\frac{2mg-mg}{m}=g$
Hence, the acceleration is different in both cases.