When a force of 50N is applied to the free end of an elastic cord, an extension of 4cm is produced. Calculate the work done on the cord.

Answer 1

F = 50 N
x = 4 cm = 0.04 m
F/x = k = 50/.04 = 1250 Newtons / meter
W = integral F dx = (1/2) k x^2
= (1/2) 1250 (.04)^2 = 1 Newton meter = 1 Joule