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 #21 (kg)/s^2# and was compressed by #3/5 m# when the ball was released. How high will the ball go?

1 Answer
Aug 13, 2017

Answer:

The height is #=2.76m#

Explanation:

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The spring constant is #k=21kgs^-2#

The compression is #x=3/5m#

The potential energy in the spring is

#PE=1/2*21*(3/5)^2=3.78J#

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 #

Then ,

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

The mass of the ball is #=0.140kg#

#PE_(ball)=3.78=0.140*9.8*h#

#h=3.78*1/(0.140*9.8)#

#=2.76m#