Question

A spring with a constant of `6 (kg)/(s^2)` is lying on the ground with one end attached to a wall. An object with a mass of `7 kg` and speed of `5 m/s` collides with and compresses the spring until it stops moving. How much will the spring compress?

Answer 1

5,4 m

Explanation:

what is the energy of a object in movement? it is given by its kinetic energy : `E_k= 1/2mv^2= 1/2 xx 7 kg xx (5m/s)^2= 87,5 J` When the object is stopped its kinetic energy is Zero. Where is now the energy that without friction and anelastic strikes preserve itself? In the energy elastic of the spring: `E_s= 1/2 K xx X^2` where X is the compress of the spring. `X = sqrt (2 E/K) = sqrt ( (175J)/(6( Kg)/s^2)) =5,4 m`