Work & Power

Work & Power

Multiple Choice

How much work you do depends on what 2 things?

• how much force needed and how big the item is

• how much force needed and how far something needs to move

• how big the item is and how far it needs to move

• what color and size the item is

Multiple Choice

What does work mean in science?

• being at a job

• the act of moving something

• the act learning in school

• being at a construction site

Multiple Choice

In which of these cases is work being done? 

• A student sleeps all night.
• A student pushes a locked door that does not move.
• A student carries his chair into another room.
• A student sits on the carpet.

Multiple Choice

Why isn't pushing against a wall work?

• a. the wall is too big

• b. the wall doesn't move when you push it

• c. the wall is an object not a person

• d. it is not a job you can earn money at

Multiple Choice

What units do we use to measure work?

• watts
• newtons
• joules
• meters

Multiple Choice

A kid throws a ball with a force of 70N over 1.1 meters. How much work did he do?

• 77 joules
• 70 joules
• 7.7 joules
• 11 joules

Multiple Choice

A 500N block is lifted 10 m. How much work was done?

• 5000 J
• 500 J
• 50 J
• 5 J

Multiple Choice

A young man exerted a force of 9,000 newtons on a stalled car but was unable to move it.  How much work was done?

• 9,000 J
• 0 J= No work

Multiple Choice

A force of 100 newtons was necessary to lift a rock.  A total of 150 joules of work was done.  How far was the rock lifted?

• 1.5m
• 15,000 m

Multiple Choice

It took 50 joules to push a chair 5 meters across the floor. With what force wast the chair pushed?

• 250N
• 10N

Multiple Choice

What is the equation for calculating power?

• distance / time
• work x time
• work / time
• force x distance

Multiple Choice

The SI unit for power is...?

• Watts
• Joules
• Newtons
• Meters

Multiple Choice

Power is a measure of how much ______ can be done in a set amount of ______.

• Work, Time
• Work, Energy
• Energy, Force
• Force, Work

Multiple Choice

What is the power of a kitchen blender if it can perform 3,750 joules of work in 15 seconds?

• 56, 250 watts
• 250 watts

Multiple Choice

While rowing across the lake during a race, John does 3960 J of work on the oars in 60 seconds. What is his power output in Watts?

• 56W

• 100W

• 66W

• None of the answers are correct

Multiple Choice

Suppose you are moving a 300N box of books. Calculate your power output in the following situations;

a. You exert a force of 60N to push the box across the floor 12m in 16 seconds.

• 300 N

• 16 J

• 36 W

• 45 W

Multiple Choice

How much power is required to lift a 30N chair, as high as 0.20m in 2s?

• 1 W

• 7 W

• 3 W

• 15 W