Force and Pressure

1. A force is a push or a pull.

1.1. Lifting

1.2. Bending

1.3. Stretching

1.4. Twisting

1.5. Squeezing

2. Effects of forces

2.1. Change the speed of a moving object

2.2. Change the shape or size of an object

2.3. Start or stop a moving object

2.4. Change the direction of a moving object

3. Instruments used to measure force

3.1. Spring balance

4. Unit of force

4.1. Newton (N)

5. Different types of forces

5.1. Elastic Spring Force

5.2. Gravitational Force

5.2.1. Exists between any two objects

5.2.2. This is the force that causes object to be attracted to the Earth.

5.3. Magnetic Force

5.3.1. Force exerted by a magnet on a magnetic material or another magnet.

5.3.2. Bar magnet have two poles.

5.3.2.1. North-seeking pole

5.3.2.2. South-seeking pole

5.3.3. Forces between magnets

5.3.3.1. Like poles repel: Magnets push away from one another

5.3.3.1.1. New node

5.3.3.2. Unlike poles attract: Magnets pull towards each other

5.4. Frictional Force

5.4.1. Occurs when two moving objects are in contact

5.4.2. Effects

5.4.2.1. Stops and slows down a moving object

5.4.2.2. Produces heat

6. Pressure is the force acting per unit area.

6.1. Pressure increases when

6.1.1. The force increases

6.1.2. The area decreases

7. Calculating Pressure

7.1. Formula

7.1.1. Force / Area

7.2. SI Unit

7.2.1. N/m2

7.2.2. Pascal (Pa)