Question

Which falling object will result in the least kinetic energy when it collides with the ground?(1 point)
Responses

100 grams of water falling at 10 m/s
100 grams of water falling at 10 m/s

100 grams of dirt falling at 15 m/s
100 grams of dirt falling at 15 m/s

10 grams of dirt falling at 2 m/s
10 grams of dirt falling at 2 m/s

10 grams of water falling at 1 m/s

Answer 1

Kinetic energy = 1/2 m v^2. Calculating each:

- 0.100 kg at 10 m/s: KE = 0.5·0.100·100 = 5 J
- 0.100 kg at 15 m/s: KE = 0.5·0.100·225 = 11.25 J
- 0.010 kg at 2 m/s: KE = 0.5·0.010·4 = 0.02 J
- 0.010 kg at 1 m/s: KE = 0.5·0.010·1 = 0.005 J

Least kinetic energy: 10 grams of water falling at 1 m/s.