Work, energy and power

A force of 10 N pushes a box 5 m in the direction of the force. How much work is done?

• 1 2 J
• 2 15 J
• 3 50 J
• 4 500 J

What is the kinetic energy of a 2 kg body moving at 3 m/s?

• 1 3 J
• 2 6 J
• 3 9 J
• 4 18 J

A machine does 600 J of work in 10 s. What is its power?

• 1 6 W
• 2 60 W
• 3 600 W
• 4 6000 W

What is the gravitational potential energy of a 5 kg mass lifted 2 m? (g = 10 m/s2)

• 1 10 J
• 2 25 J
• 3 50 J
• 4 100 J

A ball dropped from a height of 5 m reaches the ground with what speed? (g = 10 m/s2, no air resistance)

• 1 5 m/s
• 2 10 m/s
• 3 50 m/s
• 4 100 m/s

One kilowatt-hour is equal to:

• 1 3.6 x 10^3 J
• 2 3.6 x 10^6 J
• 3 1 x 10^3 J
• 4 6 x 10^4 J