Work and Power Calculations

A weightlifter lifts a 600 newton weight 1.5 meters off the ground. How much work has she done?

You have to push with 15 N of force to move it 10 meters. How much work do you do?

Tags

NGSS.MS-PS3-5

You generate 10 Watts of power when you move a weight in 4 seconds. How much work did you do?

You do 90 joules of work in 30 seconds. How much power have you generated?

You do 90 joules of work in 30 seconds. How much power have you generated?

• 30 watts

• 3 watts

• 120 watts

• 270 watts

Answer explanation

Power is calculated as work done divided by time. Here, power = 90 joules / 30 seconds = 3 watts. Therefore, the correct answer is 3 watts.

You move an 8-newton weight five meters in 4 seconds. How much power have you generated?

• 160 watts

• 10 watts

• 6.4 watts

• 17 watts

Answer explanation

Power is calculated as work done over time. Work = force x distance = 8 N x 5 m = 40 J. Power = work/time = 40 J / 4 s = 10 watts. Thus, the correct answer is 10 watts.

If a person lifts a box with a force of 500 Newtons to a height of 2 meters, how much work is done?

• 500 Joules

• 1000 Joules

• 250 Joules

• 100 Joules

Tags

NGSS.MS-PS3-2

A motor does 1500 J of work in 3 seconds. What is the power of the motor?

• 500 W

• 4500 W

• 150 W

• 300 W

Tags

DOK Level 2: Skill/Concept

If a machine does 100 Joules of work in 10 seconds, what is its power output?

• 10 Watts

• 100 Watts

• 1000 Watts

• 1 Watt

Tags

NGSS.MS-PS3-4

Which of these is a measurement of power?

• 100 joules

• 100 watts

• 100 meters per second

• 100 hertz