Question

A spring of natural length $l$ is compressed vertically downward against the floor so that its compressed length becomes $\frac{l}{2}$ .When released, the spring attains its natural length. If $k$ is the stiffness constant of spring, then what will be the work done by the spring on the floor ?

• A. zero
• B. $\frac{1}{2}kl^{2}$
• C. $\frac{1}{2}k\left(\frac{l}{2}\right)^{2}$
• D. $kl^{2}$

Answer 1

Answer: (A)

Displacement of point of application on floor is zero. so work done by spring on floor is zero.