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By pumping your legs back and forth, you manage to get swinging from an initial

ID: 1373405 • Letter: B

Question

By pumping your legs back and forth, you manage to get swinging from an initial height of about 3 feet above the ground (when the swing is at rest) to a maximum height of 6 feet above the ground. You estimate that the swing seat has a mass of about 1 kg.

8.96 J transferred into the swing , 2.99m/s

You happen to remember someone telling you that for small enough angles, the function sin(x) is well approximated by the value of x. You realize that a frictionless swing acts a lot like a spring---the net force behaves like a restoring force. You estimate your swing's chain to have a length of about 17 feet. By thinking through the forces that yield a net force on you and the swing seat, and treating the angle that the swing's chain makes with the vertical as small, you try to develop a model of the net force from the swing as a simple restoring force. What would the associated restoring force constant be assuming your mass is about 75 kg?

Explanation / Answer

F = kx for spring

restoring force will be mgsin(theta) which can be approximated as mg(theta)

mg(theta) = kx

k = (mg(theta) )/x

this would be the amount of restoring force constant