Question

21.7 kg child descends a slide 3.5 m high and reaches the bottom with a speed of 2.2 m/s How many joules of thermal energy are created due to friction as a kid slides down a slide?

Answer 1

Subtract the kinetic energy at the bottom from the potential energy loss. The remainder becomes frictional heat.

Potential energy loss:
M g H = 21.7*9.81*3.5 = 745.1 J

Kinetic energy at bottom of slide:
= (1/2) M v^2 = 52.5 J

Answer 2

692.6