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

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

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.

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

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

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

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

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

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

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

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

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

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

Exercise 3a page 43 questions

Newton’s first law: Every body continues in a state of rest or in a a state of uniform motion in a straight line unless acted on by a resultant force