UNIT 4 WORK, POWER AND SIMPLE MACHINES

Which of the following is not considered work?

• lifting a book

• pushing a shopping cart

• reading a book

• none of the above

What is the unit of work?

• joule

• newton

• watt

• none of the above

The SI unit of power is the

• joule

• newton

• watt

• none of the above

The rate at which work is done is called

• force

• power

• energy

• none of the above

A machine is a device that

• makes work easier

• increases work

• decreases work

• none of the above

Tags

NGSS.MS-PS2-1

If you exert a force of 10 N to lift a box a distance of 0.5 m, how much work do you do?

• 0.5 J

• 5 J

• 50 J

• 500 J

If you perform 30 joules of work lifting a 10 N box, how high is the shelf?

• 0.3 m

• 3 m

• 30 m

• 300 m

Tags

NGSS.MS-PS3-2

If you exert a force of 50 N to walk 4 m up a flight of stairs in 4 s, how much power do you use?

• 0.5 W

• 5 W

• 50 W

• 500 W

Which of the following is an example of a wheel and axle?

• a screwdriver

• a seesaw

• a ramp

• a pulley

The actual mechanical advantage of a machine

• is always less than 1

• is always greater than 1

• is equal to the ideal mechanical advantage

• cannot be predicted