Motion

1
Motion

• What is motion?
• How can we describe motion qualitatively(descripti
  ons) and quantitatively (numbers)?

2
Motion

• Definition Change in position
• Motion is relative-It is described compared to a
  REFERENCE POINT.
• EX You sitting in a moving car
• -you relative to the car
• -you relative to objects outside the car
• -you relative to the other 7 planets

3
Qualitative Description of Motion

• Uniform motion- constant velocity/straight path
• 2. Accelerated motion- motion that is changing
  speed or direction
• 3. Circular motion- constant velocity but is
  constantly changing direction

4
Quantitative Description of Motion

• SCALAR VECTOR
• QUANTITIES QUANTITIES
• MAGNITUDE ONLY MAGNITUDE AND
  DIRECTION
• -Distance -Displacement
• -Speed -Velocity
• -Time -Acceleration
• -Mass -Weight

5
Distance vs. Displacement

• DISTANCE-Total path traveled
• DISPLACEMENT-Change in position (final
  position-initial position) that points in the
  direction of final destination

6
Speed vs. Velocity

• SPEED- Distance/Time
• 60 km/hr
• VELOCITY- Displacement/Time

60 km/hr WEST
7
Average Speed/Velocity

• Average Speed Total Distance/Total Time
• Average Velocity

8
Instantaneous Speed
9
Acceleration

• Acceleration-Change in velocity in a given time
• -Speeding up
• Positive acceleration
• -Slowing down
• Negative acceleration
• Deceleration
• -Changing direction

10
Sample Position vs Time Graph
Position vs time for Minivans Trip

• above zero the object is moving in direction
• below zeroobject is moving in - direction

• slope velocity

• positive slope on the graph describes direction

• negative slope on the graph describes direction.

• horizontal line means position isnt changing,
  no velocity

11
Look at the graph. It shows how three runners ran
a 100-metre race. 1. Which runner won the
race? 2. Which runner stopped for a rest? 3. How
long did he stop to rest? 4. How long did Bob
take to complete the race? 5. Calculate Albert's
average speed.
12
Graphing Motion

• Positive position
• Negative constant velocity
• Positive position
• Positive constant velocity

D
T
D
T
13
Graphing Motion

• Negative position
• Negative constant velocity
• Negative position
• Positive constant velocity

D
T
D
T
14
Sample Velocity vs Time Graph
Velocity of an object traveling in a straight line

• horizontal line on the graph means constant
  velocity. Constant velocity can be zero, but is
  not always zero. The object may or may not be
  moving.

• the slope of the line is the acceleration of the
  object

• positive slope on the graph means that the
  velocity is increasing

negative slope on the graph means that the
velocity is decreasing