A 18.0 kg child descends a slide 3.40 m high and reaches the bottom with a speed of 2.48 m/s. How much thermal energy due to friction was generated in this process?

544 J

Explanation:

Potential energy at top = kinetic energy at bottom + work done by friction

PE = KE + W

mgh = ½ mv² + W

W = mgh - ½ mv²

Given m = 18.0 kg, h = 3.40 m, and v = 2.48 m/s:

W = (18.0 kg) (9.8 m/s²) (3.40 m) - ½ (18.0 kg) (2.48 m/s) ²

W = 544 J