Question

The compressed spring of a dart gun has potential energy of 50 J. If the spring constant is 200 N/m, what is the displacement of the spring?

0.5 m
0.2 m
0.7 m
0.4 m

Answer 1

Use U = 1/2 k x^2. So x^2 = 2U/k = (2·50)/200 = 0.5, hence x = sqrt(0.5) ≈ 0.707 m.

Answer: 0.7 m.