Motion and Forces

1
Motion and Forces

• UNIT 4

2
Motion

• Motion is the change in position of an object
  compared to the position of another object.

3
Reference Point

• Reference point is an object or place used to
  determine if another object is in motion.

4
Speed

• Speed is the distance an object moves in a
  particular amount of time.
• How for you go and how long it takes to get there
  (in reduced form)

5
Constant vs. Average Speed

• Constant Speed
• Traveling the same speed over a period of time.
• Distance / time

• Average Speed
• The total distance divided by the total time
  traveled.
• Total distance
• Total Time

6
Velocity and Acceleration

• Velocity is speed and direction.
• Speed He was traveling 50 km/h.
• Velocity He was traveling 50 km/h North.

• Acceleration is the change in velocity.
• Speeding up
• Slowing down
• Changing direction of motion
• Gravity has an acceleration of 9.8 m/s2 toward
  the center of the Earth

7
What Effects Motion?

• Motion is effected by different forces.
• Newtons Laws describe how forces effect objects.
• Newtons 1st Law states
• Objects at rest stay at rest and objects in
  motion stay in motion until acted upon by an
  outside force.
• If it aint movin, it aint gonna move. If its
  movin, its gonna keep movin til somethin
  changes it.

8
Forces

• No Luke, this is not about mind games.
• Forces can cause things to stay the same or to
  change.
• Examples include
• Gravity
• Contact force
• Friction
• Magnetic force
• Electrical force

9
Is the Force Balanced or Unbalanced?

• Balanced forces for the most part keep objects
  from changing

• Unbalanced forces cause changes in motion.

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Heres something to think about

• What do forces have to do with motion and
  velocity?
• How do forces effect changes in motion?
• What kind of forces are involved when you walk
  down the hallway?

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Wrap Up

• What is an object or place used to determine if
  another object is in motion?