A spring with a constant of 7 (kg)/(s^2) is lying on the ground with one end attached to a wall. An object with a mass of 4 kg and speed of 7 m/s collides with and compresses the spring until it stops moving. How much will the spring compress?

1 Answer
Jul 11, 2017

The spring will compress by =5.3m

Explanation:

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The spring constant is k=7kgs^-2

The kinetic energy of the object is

KE=1/2m u^2

The mass is m=4kg

The speed is u=7ms^-1

KE=1/2*4*(7)^2=98J

This kinetic energy will be stored in the spring as potential energy.

PE=98J

So,

1/2kx^2=98

x^2=(2*98)/(7)=28m^2

x=sqrt(28)=5.3m