Intro to Kinematics Position Distance Displacement

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Intro to Kinematics -Position -Distance -Displa
cement

• Mrs. Coyle

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Motion

• How would you describe the motion of an object?
• Motion is relative.
• Position is compared to an origin.
• Coordinate system or a reference frame.

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Linear Motion Motion in One Dimension
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Motion Diagram

• How can you visualize the motion of an object?

t0 sec
t0.5 sec
t1.0 sec
t1.5 sec
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Particle Model

• . . . .
• .

t1.0s
t1.5s
t0
t0.5s
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Position Vector
Y axis
o
x2m
x1m
Position, (m)
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Position Vectors
Y axis
o
x2m
x1m
Position, (m)
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Position Vectors
o
d11m
d22m
Position, (m)
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Vectors and Scalars

• Scalars ? Magnitude (size)
• Vectors ? Magnitude and Direction

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Distance and Displacement

• Distance (Scalar)
• Displacement (Vector)

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Displacement (Dd)- change in position.(Note Dx
can also be used as a symbol).
Dd
o
d11.5m
d22m
Position, d (m)
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Example 1

• A train after traveling on a straight line north
  for 1hour,
• is located 20km from the train station.
• After 1 additional hour of traveling in the same
  direction the train is 40km from the train
  station.
• Draw a particle model.
• Draw the position vectors for the two positions.
• Draw the displacement vectors from t1h to t2h.
• What is the total distance traveled?

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Example 2

• A jogger jogging south for 5min is 1km from the
  start. She then jogs 0.5 km north for 5min.
• 1) Draw a particle model.
• 2) Draw the position vectors.
• 3) Draw the displacement vectors from t5min to
  t10min.
• 4) What is the total distance traveled?

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Example of Position vs Time Graph
Position, (m)
20.0
10.0
A
o
1.0
0.5
1.5
2.0
Time, (s)

• At what time did the object return to the origin?
• What is the distance travelled and displacement
  at point A?