Answer to Question #168581 in Physics for john

Question

The bungee cord has an unstretched length of 20 m.

The student jumps off the bridge.

At the lowest point in the jump when the student is stationary, the extension of the bungee cord is 35m.

The bungee cord behaves like a spring with a spring constant of 40 N / m.

Calculate the energy stored in the stretched bungee cord

Answer 1

The energy stored in the stretched cord can be found as follows:

$$PE_s=\dfrac{1}{2}kx^2=\dfrac{1}{2}\cdot40\ \dfrac{N}{m}\cdot(35\ m)^2=24500\ J.$$