1. Friction
When the arrow flies from the bow, it eventually slows down, falls down and stops.
When a ball is thrown into the air, it eventually stops going up and starts coming back down to the ground where although it might bounce a few times, it eventually stops.
When you ride down hill on your bike and you want to stop before you hit the wall, you squeeze the brakes and eventually, good maintenance assumed, you stop.
When the wind blows the sails the boat will move through the water. When the wind stops blowing, the boat will eventually stop
What has surface got to do with friction?
What has shape got to do with friction?
What is friction?
What is actually going on when the arrow stops, the balls drops or you don’t actually hit the wall?

2. Useful Words Friction Air resistance Water resistance Force meter
Vocabulary
Useful Words
Friction
The action of one push or pull acting
against another push or pull where the result is fast transfer of energy resulting with heated surfaces and maybe sound as energy vibrates the air
Air resistance
Friction caused by a body moving through
air
Water resistance
Friction caused by a body moving through
water
Force meter
A piece of equipment for measuring force
Newtons
The units in which force is measured
Surface area
The face of a body

3. Force meters
3 Newtons
7 Newtons
5 Newtons
8.5 Newtons

4. Forcemeter reading in Newtons
Using Force meters
Try hanging different objects from around the classroom on the forcemeter Write down the readings you get!
Object
Forcemeter reading in Newtons

5. Force against resistance
This picture shows the same box being pushed on different surfaces.

6. Investigation: Which surface do objects slide on most easily?
Which of these surfaces will a weighted box slide across most easily? A) Vinyl B) Wood C) Carpet
When you have chosen, explain why you think this surface will be the easiest to slide across

7. Investigation (cont.)
Investigation: How are you going to test this? “What variable are you testing? (the thing that changes)” “What variable will you change?” “What variables will remain the same to make it a fair test?” “What will you measure?” Record the results as a bar chart, ask for help if you’re unsure.

8. Tyres on a car Playground slide Goalkeeper’s gloves Shoe laces
High and Low Friction
Is it best for each of the following to have a rough or a smooth surface?
Situation
High Friction
Low friction
Tyres on a car
Playground slide
Goalkeeper’s gloves
Shoe laces
A drawer
Ice skates
Climbing rope

9. Which shape do you think will travel through the water the quickest?
Water Resistance
Which shape do you think will travel through the water the quickest?
Why do you think this one will be the quickest? Test different shapes to see how quickly they move through the liquid.

10. Water Resistance
movement
water

11. Friction: the collision of forces
brakes
ice skates
Rough: high friction
Smooth: low friction
tyres
slide
goalkeeper’s
gloves
drawers
Friction:
the collision of forces
Air resistance- the opposing push of air molecules against on an object
moving through air
Water resistance-
the opposing push of water molecules against on an object
moving through air
Big area:
High
resistance
Non streamlined:
High resistance
Streamlined:
Low resistance
Small area:
Low resistance
dart
streamlined car
sail (boat)
parachute
person walking
through water
submarine
fish
boat