Unit 5.3

Fill in the blanks

_________ pushes against a moving object, such as

a car, and slows it down. The larger the _______ area of

the moving object, the more resistance there is.

• Air resistance / surface

• Water resistance / contacting

• Air resistance /

  streamlined

• Friction / front

TRUE or FALSE:

Air resistance also pushes against falling objects and slows them down.

• TRUE

• FALSE

A parachute uses air resistance to work because?.

• It is very light and smooth

• It is heavy weight and has a very big surface area

• It is very light weight

  and has a very big surface area.

• It is strong and durable

The force between two surfaces that are trying to slide past each other is called?

• Upthrust

• Friction

• Air resistance

• water resistance

Marcus is riding a bike along a gravel path. The bike's tyres and the gravel path try to slide past each other. Is this the good or bad effect of friction?

• Good

• Bad

TRUE or FALSE

Air resistance and water resistance are types of friction.

• TRUE

• FALSE

Fill in the blank

Both air resistance and water resistance are sometimes called ________

• friction

• drag

• upthrust

• non-contact forces

What will happen when you push a football in a swimming pool?

• It will blow up

• It will stay down under water

• It will float back on to the surface

• It will sink down to the bottom

Why do swimmers try to copy the streamlined shape of fish?

• Because it causes less disturbance of the water and therefore less drag

• Because it will help them float in the water

• Because it reduces upthrust and makes them look sleek

• Because streamlined shape help increase water resistance

What do we call the force that pushes things up in water?

• drag

• Water resistance

• Buoyancy

• Air resistance