work and power

What is the formula for calculating work?

• • Work = Force / Displacement

• • Work = Force × Displacement

• • Work = Displacement / Force

• • Work = Force - Displacement

Which of the following situations involves zero work?

• • Pushing a car that moves

• • Lifting a box upwards

• push a wall

• • Dropping a stone

What is the SI unit for power?

• • Joule

• • Newton

• • Watt

• • Meter per second

Which type of work occurs when force and displacement are in the same direction?

• • Positive work

• • Negative work

• • Zero work

• • Opposing work

If a person does 40 J of work in 4 seconds, what is the power used?

• • 10 W

• 20 W

• • 8 W

• • 160 W

Which of these situations represents negative work?

• • Pulling a sled forward

• • Slowing down a car with brakes

• • Lifting a box

• • Holding an object still

If a person pushes a box with 15 N force but it doesn’t move, the work done is:

• • 15 J

• • Zero

• • 30 J

• • 45 J

• The force applied to lift a box results in 200 J of work. If the box was lifted 2 meters, what force was applied?

• • 400 N

• • 200 N

• • 100 N

• • 50 N

Tags

NGSS.MS-PS2-2

Which formula represents power if work and time are known?

• • Power = Work × Time

• • Power = Work ÷ Time

• • Power = Time ÷ Work

• • Power = Work + Time

If a machine does 600 J of work in 3 seconds, what is the power output of the machine?

• • 200 W

• • 600 W

• • 900 W

• • 1800 W