Question

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


a ball with a mass of 10 grams falling at 1 m/s
a ball with a mass of 10 grams falling at 1 m/s

a toy plane with a mass of 10 grams falling at 2 m/s
a toy plane with a mass of 10 grams falling at 2 m/s

a toy plane with a mass of 100 grams falling at 15 m/s
a toy plane with a mass of 100 grams falling at 15 m/s

a ball with a mass of 100 grams falling at 10 m/s
a ball with a mass of 100 grams falling at 10 m/s

Answer 1

Kinetic energy = 1/2 m v^2. Compute each (m in kg):

- 10 g (0.01 kg), 1 m/s: KE = 0.5·0.01·1^2 = 0.005 J
- 10 g (0.01 kg), 2 m/s: KE = 0.5·0.01·2^2 = 0.02 J
- 100 g (0.1 kg), 15 m/s: KE = 0.5·0.1·15^2 = 11.25 J
- 100 g (0.1 kg), 10 m/s: KE = 0.5·0.1·10^2 = 5 J

Least kinetic energy: the 10 g ball falling at 1 m/s (0.005 J).