Question

A spring block system is placed on a rough horizontal floor. The block is pulled towards right to give the spring some elongation and released.The block will have maximum velocity when:

• A. the spring force becomes zero
• B. the frictional force becomes zero
• C. the net force becomes zero
• D. the acceleration of block becomes zero

Answer 1

Answer: (C), (D)

The correct options are
C the net force becomes zero
D the acceleration of block becomes zero

Force, $F=ma=m\frac{dv}{dt}$ where $a$ is the acceleration.
Velocity is maximum when $\frac{dv}{dt}=0$, thus the net force and acceleration become zero.
Ans:(C),(D)