Question

The ball of mass $50g$ is suspended by a spring with a force constant $K=49$ $N/m$. The ball is raised to the position at which the spring is not tensioned and is released without a push. The ball fall through a maximum distance of

• A. $0.01m$
• B. $0.02m$
• C. $0.04m$
• D. $0.03m$

Answer 1

The correct option is B $0.02m$

The potential energy of ball at top position will be equal to potential energy of ball at lower position plus the elastic energy stored in the spring.

Assuming the lower position as the reference for potential energy.

$U_i=U_i+U_{spring}$

$mgh=0+\frac{1}{2}K{h}^2$

$\frac{50\times 9.8\times h}{1000}=\frac{49\times h^2}{2}$

$h=0.02m$