Forces And Pressure

1. Forces

1.1. A force is a push or pull

1.2. The SI unit for force is Newton (N)

1.3. Forces can be measured with a force meter

2. Effects of Forces

2.1. Change the shape or size of an object

2.2. Start an object moving or stop a moving object

2.3. Speed up or slow down a moving object

2.3.1. New node

2.4. Change the direction of a moving object

3. Kinds of Forces

3.1. Gravitational Force (Gravity)

3.1.1. Pulls objects towards the center of the Earth

3.1.2. The force of gravity pulling down an object is called its weight

3.2. Magnetic Force

3.2.1. Force of attraction produced by magnets on objects made of iron or steel

3.2.2. Magnets can attract or repel other magnets

3.3. Frictional Force (Friction)

3.3.1. Produced when two moving objects are in contact. It opposes and slows down movement

3.3.2. Can be useful in everyday life

3.3.3. Friction can be a nuisance. Lubricants, streamlining, using ball bearings and smooth surfaces are ways to reduce friction

3.4. New node

4. Pressure

4.1. The force exerted per unit area

4.2. Increases when force force increases and when area decreases