Chapter 4 Review

For work to be done on an object,

• some force need only be exerted on the object

• the object must move some distance as a result of the force

• the object must move, whether or not a force is exerted on it

• the object must not move

If you exert a force of 20 newtons to push a deck 10 meters, how much work do you do on the desk?

• 200 joules

• 30 joules

• 10 joules

• 100 joules

The mechanical advantage of a machine is the number of times a machine increases

• the distance an object moved

• the amount of friction

• the change in direction

• the force exerted on the machine

A simple machine that might be thought of as an inclined plane that moves is a

• lever

• wheel and axle

• wedge

• pulley

One example of a compound machine is a

• door

• pliers

• bicycle

• shovel

How can a hockey stick be considered a machine?

• It increases force

• It multiplies distance

• It changes direction

• It reduces friction

If tight scissors have an efficiency of 50 percent, half of your work is wasted due to

• the output force

• the input force

• friction

• changes in direction

Power is measured in units called

• Joules

• pounds

• watts

• newtons

The wedge, screw, and lever are all

• simple machines

• compound machines

• found in the human body

• 100 percent efficient

In order to do work on an object, the force you exert must be

• the maximum amount of force you are able to exert

• in the same direction as the object's motion

• in a direction opposite of Earth's gravitational force.

• quick and deliberate