Question

Which object has the greatest kinetic energy?(1 point)
Responses

a yellow car with a mass of 500 kg moving at 12 m/s
a yellow car with a mass of 500 kg moving at 12 m/s

a blue car with a mass of 500 kg moving at 30 m/s
a blue car with a mass of 500 kg moving at 30 m/s

a green car with a mass of 500kg moving at 21 m/s
a green car with a mass of 500kg moving at 21 m/s

a red car mass of 500 kg moving at 3 m/s

Answer 1

Kinetic energy = 1/2 m v^2. All masses are 500 kg, so the largest speed gives the largest KE. The blue car (30 m/s) has the greatest kinetic energy.

KEs:
- Yellow: 0.5·500·12^2 = 36,000 J
- Blue: 0.5·500·30^2 = 225,000 J
- Green: 0.5·500·21^2 = 110,250 J
- Red: 0.5·500·3^2 = 2,250 J

Answer: the blue car.