Motion and Forces

1
Motion and Forces

• Section 2-3

2
What is a force?

• a door
• a rubber band
• Shove a book across the table
• Some are obvious (car hits tree), others are not
  (floor pushing on feet).

3
Effects of Forces on Objects

• Does the object move when a force is exerted on
  it?
• Balanced forces
• Unbalanced Forces

4
Inertia and Mass

• Inertia
• Compare the inertia of bowling ball with tennis
  ball
• More mass

5
Newtons first law

• An object remains in motion unless a
  net force acts on it. An object
  at rest unless a
  net force acts on it. (INERTIA)
• Wheelbarrow with rake on top strikes a rock.
  What happens?
• Why do cars have seatbelts?

6
Friction

• Force that that
  are touching.
• Amount of friction depends on The
• , and the
  force pressing the surfaces together.