1.

A force of 600 N elongates a spring from its natural length of 18 cm to a length of 20 cm. What is the work done?(a) 116J(b) 114J(c) 118J(d) 120JI have been asked this question during an interview for a job.This key question is from Work Done by a Variable Force topic in division Work, Energy and Power of Physics – Class 11

Answer»

The correct choice is (b) 114J

The BEST explanation: The force on a spring stretched by x meters is given by F = K*x where k is the spring constant. So, 600 = k*(2/100). Now k = 3*10^4, and hence F = 30000*x. W = \(\int_{x1}^{x2}\)F * dx = \(\int_{0.18}^{0.2}\)30000 * x * dx = 114 J.



Discussion

No Comment Found

Related InterviewSolutions