Forces and Pressure

1. Extension spring balance The spring stretches when a force pull on it The greater the force, the more the spring stretches

2. Force

2.1. A push or pull

2.2. Causes Change

2.2.1. Effects

2.2.1.1. Move a stationary object Make an object move faster or slower Stop a moving object Cause an object to change direction Change the shape of an object

2.3. Important forces are: Gravitational Force Frictional Force Magnetic Force

2.4. Measured in Newtons

3. Pressure

3.1. Pressure is the force acting per unit area.

3.2. pressure increases when: The force increases; or The area decreases

3.3. SI Unit : N/m2 or Pascal (Pa)

4. We cant see a force, but we can observe the effects of a force.

5. How to measure Force? By using force meters or Newton meters

6. Compression Spring Balance The spring compresses when a force push on it The greater the force, the more the spring compresses

7. Pressure = Force/Area