A spring whose natural length is 20 cm is stretched to a length of 35 cm by a 2-N force. Find the work done in stretching the spring.
A) 0.15 J
B) 30 J
C) 0.7 J
D) 40 J
E) 0.3 J

Question

Quizplus · Accepted Answer

Work done = (1/2) * k * (change in length)^2k = F / (change in length) = 2 N / (35 cm - 20 cm) = 2 N / 15 cm = 0.133 N/cmWork done = (1/2) * 0.133 N/cm * (15 cm)^2 = 0.15 J

A Spring Whose Natural Length Is 20 Cm Is Stretched