A 200 g mass is attached to a spring of spring constant k. The spring is compressed 15 cm from its equilibrium value. When released the mass reaches a speed of 5 m/s. What is the spring constant (in N/m)?

Answer 1

w*(amplitude) = maximum velocity
Solve for w (in radians/second) and then use
w = sqrt(k/m) to get k, the spring constant
Amplitudes and velocities must be in meters and m/s. Mass must be in kg

Answer 2

0.25m