Describe the motion of the mass m shown in figure. The walls and the block are elastic.

Explanation

The block reaches the sring with a speed v. It now compresses te spring . The block is decelerated due toteh sprng force comes to rest when `1/2mv^2=1/2kx^2` and returns back. It is accelerated due toteh spring force till the spring acquires its N/Atural length. The contact of the block with the spring is now broken. At this instant it has regained its speed v (towards left) as teh sprig is unstretched and no potential energy is stored. This proces takes half the period of oscillation, i.e. `pisqrt(m/k)`. The block strikes the left wall after a time `L/v` and as the collision is elstic it rebounds with the same speed v. After a time `L/v`, it again reaches the spring and the process is repeated. The block thus undergoes periodic motion with time period `pisqrt(m/k)+(2L)/v`