Question

A spring of force constant k is cut into two pieces whose lengths are in the ratio 1 : 2. What is the force constant of the longer piece ?(a) $\frac{k}{2}$(b) $\frac{3k}{2}$(c) 2k (d) 3k

Answer 1

Answer :- b) 3k/2

Length of the spring be L.

When spring is cut into 2 pieces, length will become

L1= L/3

L2=2 x L/3   -- Longer Piece --- (1)

K is inversely proportional to Length of the spring. K =a/L. Substitute (1) in this equation.

So force constant will be become 3k/2.

So answer is b - 3k/2