Yr7 P1.3 Drag forces and friction

What is friction?

• A force that acts between two objects not touching

• A force between two surfaces that resists motion

• A pulling force caused by gravity

What are two effects of friction?

• Speeds objects up and increases their temperature

• Slows objects down and stops them moving

• Increases pressure and cools the surface

Why is friction useful when walking?

• It keeps your feet warm

• It pushes you backwards

• It stops your foot from slipping

What do we call the process of adding oil or grease to reduce friction?

• Acceleration

• Lubrication

• Streamlining

Why might the hinges of a door need to be lubricated?

• To make the door lighter

• To help the surfaces slide more easily past each other

• To increase the noise it makes

What is a drag force?

• A force that pushes objects forward in space

• A type of friction that occurs in gases or liquids

• A magnetic force acting on moving objects

What is the name of the drag force acting on an aeroplane in flight?

• Gravity

• Air resistance

• Friction

What happens when a swimmer moves through water?

• They speed up from water resistance

• Water particles push them forward

• Water particles push against them, causing drag

What does "streamlined" mean?

• Having a bumpy shape to increase friction

• Shaped to move easily through air or water

• Covered in oil or grease

Why do bicycle brake blocks need replacing over time?

• They melt from heat

• Friction wears them down

• The wheels make them slippery