A spring with a constant of 9 kgs2 is lying on the ground with one end attached to a wall. An object with a mass of 2 kg and speed of 12 ms1 collides with and compresses the spring until it stops moving. How much will the spring compress?

2 Answers
Jun 11, 2017

The compression is =5.66m

Explanation:

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The spring constant is k=9kgs2

The kinetic energy of the object is

KE=12mu2

KE=122(12)2=144J

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

PE=144J

So,

12kx2=144

x2=21449=32m2

x=32=5.66m

Jun 11, 2017

The displacement of the spring, x, will be 4 m.

Explanation:

The kinetic energy of the moving object will be Ek=12mv2=12×2×122=144 J.

This will be converted to spring potential energy: Esp=12kx2.

Rearranging: x=Espk

We can substitute in the calculated value of Ek for Esp:

x=Espk=Ekk=1449=123=4 m