What is the force (in Newtons) that holds the spring stretched at the same distance (13 cm)?

Question

Work of 4 Joules done in stretching a spring from its natural length to 13 cm beyond its natural length. What is the force (in Newtons) that holds the spring stretched at the same distance (13 cm)?

_______ Newtons

Answer 1

F = kΔx = 0.13k;

Work W = k(Δx)²/2 = k(0.13)²/2 = 4; F/4 = 2/0.13; F = 8/0.13 = 61.54 N