Question

A spring of weight W and force constant k is suspended in a horizontal position by two light strings attached to its two ends. Each string makes an angle θ with the vertical. The extension of the spring is

(a) (W/4k)tan θ

(b) (W/2k)tan θ

(c) (W/4k)sin θ

(d) 0

Answer 1

Correct Answer is: (b) (W/2k)tan θ

Let T = tension in each string.

2Tcos θ = W and Tsin θ = kx, x = extension of spring

or (W/2cos θ) sin θ = kx or x = w tan /2k.