1. Forces
Lesson Objective:
Understand the types of Forces that exist and Newton’s third law

2. Name of Force Cause Direction
Weight Gravity pulling Towards the ground
Normal Contact Something touching Perpendicular to
the surface
Friction Where there are rough In opposite direction
surfaces in contact to the movement
Driving Motors or Engines In same direction as
the movement
Resistance Moving through In opposite direction a fluid to the movement
Tension Pulling with a string/bar Outwards, along the
line of the string/bar
(Compression Pushing in on a bar Inwards, along the line)
of the string/bar

3. Newton’s Third law states:
When one object exerts a force on another there is always a reaction of the same kind which is equal and opposite in direction to the acting force.

4. A chair standing and stationary on a flat surface
Label all the forces on the chair

5. A chair standing and stationary on a slopping surface
Label all the forces on the chair

6. A chair standing and stationary with a person sitting on it
Label all the forces on the chair

7. A chair standing and stationary with a person sitting on it
Label all the forces on the person

8. A chair standing and stationary on a slopping surface with a person sitting on it. Label all the forces on the person.

9. A chair standing and stationary on a slopping surface with a person sitting on it. Label all the forces on the chair.

10. Two large bricks stacked, standing and stationary on a flat surface with a person standing on the top
Label all the forces on the bottom brick

11. Two large bricks stacked, standing and stationary on a slopping surface with a person standing on the top
Label all the forces on the bottom brick

12. A person free-falling from a plane
Label all the forces on the person

13. Label all the forces on the water-skier
A water skier being pulled by a speedboat