9th Grade- Chapter 8 & 9 Test Review

Work may be measured using units of:

• watts.

• newtons.

• joules

• newtons per second.

The equation used to calculate work when force is applied to move an object some distance is:

• Work = force + distance

• Work = force ÷ distance

• Work = distance ÷ force

• Work = force × distance

Tags

NGSS.MS-PS3-5

If forces A, B and C are equal, the work done by the forces as they are exerted on the box is:

• greatest for force A.

• greatest for force B.

• greatest for force C

• the same for all forces.

An automobile engine exerts a force of 500 newtons on a car to travel 4,000 meters. What is the amount of work done by the engine?

• 0.125 joules

• 8 joules

• 4,500 joules

• 2,000,000 joules

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

NGSS.MS-PS3-4

A 60-newton block at rest at the bottom of a frictionless incline plane is pushed up the incline:

The amount of work done against gravity is ____ joules.

• 0

• 20

• 60

• 180

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-4

NGSS.MS-PS2-4

Robert lifts a 150-newton bucket of water 0.5 meters in 3 seconds. What is the amount of work done on the bucket?

• 25 joules

• 25 watts

• 75 joules

• 75 watts

Tags

NGSS.MS-PS3-5

Jake, who weighs 680 newtons, climbs a 6 meter ladder in 8 seconds. What was Jake’s power?

• 510 watts

• 4080 watts

• 5440 watts

• 32640 watts

Tags

NGSS.MS-PS3-5

NGSS.MS-PS3-4

Which of the following improves the efficiency of a machine?

• Reducing friction

• Adding more energy

• Running it faster

• Increasing friction

Tags

NGSS.MS-ETS1-1

The work output of a machine:

• is always greater than the work input.

• is always less than the work input.

• must be equal to the work input.

• is always changing the work input.

How much power is necessary to do 50 joules of work in 5 seconds?

• 5 watts

• 10 watts

• 50 watts

• 250 watts