Potential Energy Physics Example 4

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Example 4

easy
A bungee cord has an effective spring constant k=100 N/mk = 100 \text{ N/m}. If it stretches 3 m3 \text{ m} beyond its natural length, how much elastic potential energy is stored?

Solution

  1. 1
    Use PE=12kx2PE = \frac{1}{2}kx^2.
  2. 2
    PE=12(100)(3)2=12(100)(9)=450 JPE = \frac{1}{2}(100)(3)^2 = \frac{1}{2}(100)(9) = 450 \text{ J}.

Answer

PE=450 JPE = 450 \text{ J}
Elastic potential energy grows with the square of the stretch. Tripling the stretch from 1 m to 3 m stores nine times as much energy, not three times.

About Potential Energy

Energy stored in a system due to the position or configuration of its parts, ready to be converted into kinetic or other forms of energy.

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Example 1 easy

A spring with spring constant [formula] is compressed by [formula]. What is the elastic potential en

Example 2 medium

A spring ([formula]) is stretched [formula]. How much work was done to stretch it?

Example 3 medium

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