The staples inside a stapler are kept in place by a spring with a relaxed length of 0.116 m. if the spring constant is 46.0 n/m, how much elastic potential energy is stored in the spring when its length is 0.146 m?

The elastic potential energy of a spring is computed by: 1/2 * k * x^2

where:

k = spring constant = 46 N/m

x = displaced length = 0.146 - 0.116 = 0.03 m = 3 cm

PE = 0.5*46*.023^2 = 0.012167 J = 12.17 mJ is the elastic potential energy stored in the spring.