Question

What is the potential energy of a spring that is compressed 0.65 m by a 25 kg block if the spring constant is 95 N/m?

1.6 J
7.9 J
15 J
20 J

Answer 1

Potential energy U = 1/2 k x^2 = 0.5 × 95 N/m × (0.65 m)^2 = 0.5 × 95 × 0.4225 = 20.07 J ≈ 20 J.