Motion

1
Motion

• ISCI 2002

2
Speed

• Speed change in distance over time
• Speed ?d / ?t
• Constant vs. Average Speed
• Speed is a scalar quantity
• No directional properties

3
Velocity

• Velocity includes the speed of an object plus
  direction.
• Velocity ?d / ?t direction!
• Displacement
• Object moves from one location to another
• Distance and direction from a starting point

4
Displacement
5
Velocity and Displacement are Vectors

• Vectors have both magnitude and a direction
• Velocity, acceleration, displacement, etc.
• Vectors are represented by arrows

6
Vector Summation

• Parallel vectors may be summed
• When vectors are at right angles
• (a) Parallelogram Rules
• (b) use trigonometry rules to solve
• Pythagorean Theorem

7
Vector Addition
8
Paralleogram Law

• The so-called parallelogram law gives the rule
  for vector addition of two or more vectors. For
  two vectors and , the vector sum is obtained by
  placing them head to tail and drawing the vector
  from the free tail to the free head.

9
Vector Resultant
10
Acceleration

• Acceleration is a change in the velocity of an
  object.
• Acceleration ?v / ?t
• When you change directions, slow down, speed up,
  turn you are undergoing acceleration.
• Acceleration may be () or (-)

11
Instantaneous Speed and Velocity

• Speed or velocity at any given moment in time
• Speedometer in your car

12
Motion and Graphs

• Graphs
• Straight-line or linear slope indicates a direct
  or proportional relationship between the
  variables
• Speed or velocity at that specific time
• Non - proportional
• Slope of the line tangent to the curve of the
  line
• Positive or Negative relationship between
  variables

13
Graphical Slopes

• Slope rise/run
• Change in position (y) over time (x)

14
Calculating the Slope of a Graph
15
Distance-Time Graphs
Constant velocity (10 m/s) No acceleration
Changing, positive velocity acceleration
(change in velocity)
16
Constant Velocity No Acceleration
17
Velocity Time Graphs
Zero Acceleration
18
Constant Velocity Zero Acceleration
19
Velocity-Time Graphs (Acceleration)