Question

A ball with a mass of `360 g` is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of `15 (kg)/s^2` and was compressed by `4/3 m` when the ball was released. How high will the ball go?

Answer 1

The height reached by the ball is `=3.78m`

Explanation:

The spring constant is `k=15kgs^-2`

The compression of the spring is `x=4/3m`

The potential energy stored in the spring is

`PE=1/2kx^2=1/2*15*(4/3)^2=13.33J`

This potential energy will be converted to kinetic energy when the spring is released and to potential energy of the ball

`KE_(ball)=1/2m u^2`

Let the height of the ball be `=h`

The acceleration due to gravity is `g=9.8ms^-2`

Then ,

The potential energy of the ball is `PE_(ball)=mgh`

Mass of the ball is `m=0.360kg`

`PE_(ball)=13.33=0.360*9.8*h`

`h=13.33*1/(0.360*9.8)`

`=3.78m`

The height reached by the ball is `=3.78m`