A ball with a mass of 140 g is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of 16 (kg)/s^2 and was compressed by 7/3 m when the ball was released. How high will the ball go?

1 Answer
May 11, 2018

The height reached by the ball is =31.75m

Explanation:

![http://www.mwit.ac.th](https://useruploads.socratic.org/BDdx3oLBRcinM95cLQLj_spring%20pot%20energy.gif)

The spring constant is k=16kgs^-2

The compression of the spring is x=7/3m

The potential energy stored in the spring is

PE=1/2kx^2=1/2*16*(7/3)^2=43.56J

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=0.140kg

PE_(ball)=43.56=0.140*9.8*h

h=43.56*1/(0.140*9.8)

=31.75m

The height reached by the ball is =31.75m