1. Force
1.1. Effects of forces
1.1.1. Change the direction of a moving object
1.1.2. Start a stationary object
1.1.3. Stop a moving object
1.1.4. change the speed of a moving object
1.1.5. Change the shape and size of an object
1.2. is a push or a pull
1.3. Instruments for measuring a force
1.3.1. Spring balance
1.4. Types of forces
1.4.1. Frictional force
1.4.1.1. opposes the movement of an object
1.4.1.1.1. produces heat
1.4.1.1.2. slows down an object
1.4.1.1.3. makes movement difficult
1.4.1.1.4. causes wear and tear
1.4.1.2. ways of reducing friction
1.4.1.2.1. smooth surfaces
1.4.1.2.2. lubricant
1.4.1.2.3. ball bearings
1.4.1.2.4. streamlining
1.4.2. Gravitational force
1.4.2.1. is the force acting between two objects
1.4.2.1.1. pull us down to Earth
1.4.2.1.2. keep us from floating
1.4.2.2. the greater the force of gravity, the higher the pressure
1.4.3. Magnetic force
1.4.3.1. force between magnets
1.4.3.1.1. like poles repel
1.4.3.1.2. unlike poles attract
2. Pressure
2.1. amount of force acting perpendicularly on an object
2.1.1. can be increased/decreased by
2.1.1.1. decreasing the area