1. Forces
Push
Pull
Twist

2. FORCES CAN…… Change the direction that objects move in
This could mean an object goes from forward to backward
An object could speed up or slow down
Unbalanced forces make an object move in the direction of the biggest force.
If all the forces are equal the object does not move
Arrows can be used to show the direction and size of a force
Change the shape of objects
This can be permanent or temporary
The force changes the way the particles in the object are organised

3. Types of Forces Contact Forces Some examples are:
These are forces that touch the object that they are working on
Some examples are:
pushing a door
Forces acting at a distance
These are forces that we can’t always see.
Some examples are:
Magnetic fields

4. Force Meters Measures the size of a force
The spring stretches at a constant rate
The unit is Newtons
The symbol is N
1Newton = 10 grams

5. Gravity is a Force
The force of gravity depends on the size of the planet that your on
The earth has 6 times the gravity of the moon
If your mass on earth was 60kg your weight would be 600N (on the moon it would be 100N)
It you want to overcome gravity (i.e. get of the ground) your force needs to be stronger than gravity in the opposite direction

6. Friction is a Force Friction slows objects down
It opposes the force that is moving the object
E.g. a helicopter is being dragged down by gravity. Friction with the air keeps the helicopter in the air longer
Friction can be helpful
E.g. keeping you car on the road
Friction can cause damage
E.g. it can wear out parts in an engine

7. Machines Overcome Some Forces
A machine can make work easier
Pulleys, wheels, ramps and levers can be used to spread the work out, this means the same forces is needed but in smaller amounts

8. Key Words
(write your key words on the last page in your books)