1. Unit 6.3 physics Newtons 1st law

2. Inertia • An object at rest will stay that way unless a force acts on it • An object in motion will continue to move in the same direction and speed until a force acts on it.

3. What is a force? A force is a push, pull or twist that can cause an object to • Accelerate (increase its speed) • Decelerate (decrease its speed) • Change its direction • Change its shape

4. Types of forces [contact] • Friction • Air resistance or drag • Buoyancy • Surface tension • Lift • Thrust

5. Types of forces [non contact] • Weight • Electrostatic • Magnet

6. Discussion • Explain why you feel heavier than normal at the bottom of a roller coaster and lighter at the top? • Outline what is the purpose of headrest in a car. • Explain why you should wear seatbelts in a car.

7. Place the following words in a sentence • Force • Contact • Inertia • Buoyancy • Surface Tension • Lift • Thrust • Weight