A spring of natural length l is compressed vertically downward against the floor so that its compressed length becomes (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 ?

Question

A spring of natural length l is compressed vertically downward against the floor so that its compressed length becomes (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) (1/2)kl2 (C) (1/2)k((l/2))2 (D) kl2

Tardigrade Admin · Accepted Answer

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

Q. 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 ?

zero

$\frac{1}{2} k l^{2}$

$\frac{1}{2} k (\frac{l}{2})^{2}$

$k l^{2}$

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

Q. A spring of natural length l is compressed vertically downward against the floor so that its compressed length becomes 2l​ .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 ?

zero

21​kl2

21​k(2l​)2

kl2

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

Q. 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 ?

$\frac{1}{2} k l^{2}$

$\frac{1}{2} k (\frac{l}{2})^{2}$

$k l^{2}$