Which of these is NOT a simple machine?

• Pulley

• Wheel

• Door

• Lever

What is the unit of work done?

A special type of wheel that is toothed is called a ...

A force of 0.5 N pushes on a cart over a distance of 300m. The work done is ____ J.

Match the following simple machines to their correct examples.

• Jar lid

• Wedge

• Escalators

• Inclined plane

• Broom

• Lever

• Nail

• Screw

Single wedge or double wedge?

Groups:

(a) SINGLE

,

(b) DOUBLE

• Doorstop

• Nail

• Razor blade

• Chef's knife

• Axe

A work of 80 J was done by a box sliding down a 5m long ramp. What was the force (in N) that was pushing the box down the slope?

Label the following classes of levers...

a

b

d

Class A

Class C

Class B

Class D

Class 1

Class 2

Class 3

Class 4

Which statement about a nutcracker is FALSE ?

• It is a class 2 lever.

• It is a mechanical man-made system.

• It makes work easier by changing force.

• It is in the same simple machine as a baseball bat.

Physical systems can be divided into ​ (a)   , such as a water cycle, and​ (b)   such as a bus, refrigerator or can-opener.

• natural
• social
• human-made
• mechanical
• electrical