Year 7 Science Semester 2 Exam Revision

What will cause an object to move?

• Applied forces
• Balanced forces
• Unbalanced forces

Balanced or Unbalanced?

• Balanced 
• Unbalanced

What pulls a ball back to earth?

• Gas
• Gravity
• Friction
• Molecules

Match the following forces to their definitions.

• Force moving away from the body

• Gravity

• Opposing force between two surfaces that are touching

• Pull

• Force that pulls things down towards the ground

• Friction

• Force moving towards the body

• Push

Which of the following is an example of friction that is helpful?

• Brakes used on a bike
• Tires from a car on the road
• Tread on the bottom of your shoes
• All are examples that are helpful

Which of the following is an example of friction that is harmful?

• Pencil marking on paper
• Engine parts wearing out
• sand placed on ice in the winter
• Using an eraser to erase marks

For a lever to be a first class lever the fulcrum needs to be ..

• between the load and the effort
• on one side and the load and effort on the other side 
• on the same side as the load arm. 

A bottle opener is a .....

• Pulley

• Lever

• Inclines plane

A good example of a second class lever is the ...

• Can-opener
• Wheelbarrow 
• hammer 
• tongs 

Third class levers are said to be speed multipliers. 
examples of third class levers include all of the below except .....

• a door handle 
• baseball bat 
• tennis rachet 
• golf club