Physics. Topic: Simple Machines

1. State whether the following statements are true or false:

a. A machine performs work by itself.

• False

• True

b. Efficiency is the ratio of the work input to the work output.

• False

• True

When M.A. is equal to one, the effort needed is equal to the load.

• False

• True

d. The resistive or opposing force to be overcome by a machine is called load.

• True

• False

2. What do you understand by the term machine?

• A machine is a device which allows people to do work with less effort.

• A machine is a device which not allows people to do work with less effort.

This type of simple machine uses a wheel to change the direction of a force.

• wedge
• lever
• pulley
• screw

All simple machines help make work _________.

• harder
• smaller
• lighter
• easier

This simple machine allowed Elijah to lift a heavy rock.

• wedge
• lever
• screw
• inclined plane

Simple machines can change the amount of_______ needed to do work.

• gravity
• people
• force
• pulley

This simple machine helped Olivia move the weight across the room.

• lever
• wedge
• wheel and axle
• screw