A 17 kg child descends a slide 3.5 m high and reaches the bottom with a speed of 1.5 m/s. How much thermal energy due to friction was generated in this process?

Answer 1

initial PE=FinalKE-thermalenergylost
mgh=1/2mv^2-thermalenergy lost.

Answer 2

a 0.145 kg baseball pitched at 39.0 m/s is hit on a horizontal line drive straight back toward the pitcher at 52.0 m/s.if the contact time between bat and ball is 0000.3 s,calculate the average force between the ball and bat during contact.

Answer 3

325J