A pendulum has a mass of 3-kg, a length of 1.3 meter, and swings through a (half) arc of 30 degrees. To the tenth of a Joule, what is its maximum Kinetic Energy?

Answer 1

Calculate the potential energy gain when swinging to maximum height.

m g L (1 - cos30)

Answer 2

so do you just plug everything into this equation and that's it? What exactly do is this expression for?

Answer 3

Yes, that is the answer. Plug in and get the number. It represents the difference between maximum and minimum potential energy, and that equals the maximum kinetic energy, since at maximum P.E. (top of swing), the K.E is zero.