force and pressure

1. force-meters

1.1. Spring balances

1.1.1. extension spring balances

1.1.2. compression spring balances

1.2. Dynamometers

2.  Gravitational force

2.1. also known as gravity

2.2. depends on mass

2.3. force that pulls objects towards the Earth

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

3. force is a push or pull

4. effects of force

4.1. change the speed of a moving object

4.2. Change the shape or size of the object

4.3. Start an object moving or stop a moving object

4.4. Change the direction of a moving object

5. How can we measure a force?

6. important forces around us

6.1.  Frictional force

6.1.1. Force exerted by a surface as an object moves across it

6.1.2. slows down and stops a moving object

6.1.3. produces heat

6.2.  Magnetic force

6.2.1. either a push or pull

6.2.2. force of attraction produced by magnets on objects made of iron or steel

7. What is pressure?

7.1. The force exerted per unit area

8. How can we decrease pressure?

8.1. when force decreases or area increases

9. How can we increase pressure?

9.1. when force increases or area decreases

10. Calculating Pressure

10.1. SI Unit: Pascal (Pa)

10.2. 1 Pa=1N/m2

10.3. Pressure=Force/Area

10.4. Force: Newton (N)

10.5. Eg: 200N/10cm2=20N