Question

A 2 kg block slides on a horizontal floor with a speed of 4 m/s. It strikes an uncompressed spring, and compresses it till the block is motionless. The kinetic friction force is 15 N and spring constant is 10,000 N/m. The spring compresses by :-

Answer 1

Change in kinetic energy=work done by the force

$0.5m{v}^2=0.5k{x}^2$

$x=v\times \sqrt{\frac{m}{k}}$

$x=4\times \sqrt{\frac{m2}{{10}^4}}$

$=5.657$cm.