Question

A ball of mass 100 g is placed on a compressed spring. The spring has stored 5 J of potential energy due to compression. If the spring is released and its energy is converted to kinetic energy of the ball, calculate the velocity of the ball after the spring is released.

• A. 25 m/s
• B. 20 m/s
• C. 10 m/s
• D. 5 m/s

Answer 1

The correct option is C 10 m/s

Given,

Potential energy of the spring, PE = 5 J

Mass of the ball, m = 100 g = 0.1 kg

Let velocity and kinetic energy of the ball be v and KE, respectively.

As the potential energy of the spring is converted to kinetic energy of the ball,

KE = PE = 5 J

$\frac{1}{2}m{v}^2$ = 5

$\frac{1}{2}$ × 0.1 × $v^2$ = 5

$v^2$ = 100

v = 10 m/s