# 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  9 m/s collides with and compresses the spring until it stops moving. How much will the spring compress?

Jan 20, 2017

The Kinetic energy of the object $E k = \frac{1}{2} m {V}^{2}$becomes the elastic energy of the spring $E s = \frac{1}{2} m {X}^{2}$ so
$m {V}^{2} = K {X}^{2}$
$X = \sqrt{\frac{m}{k}} V$
$X = \sqrt{\frac{4 k g}{7 k \frac{g}{s} ^ 2}} 9 \frac{m}{s}$ = 6,8 m