IPC 08: Speed

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IPC 08 Speed Acceleration
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Objectives

• Define Speed, velocity, and acceleration.
• Explain the difference between speed and
  velocity.
• Explain the difference between velocity and
  acceleration.
• Use speed, velocity, and acceleration to solve
  problems involving linear motion.

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Speed is the ratio of the total distance traveled
divided by the total time.
Distance traveled Time interval
Speed
d

• d distance
• t time
• s speed

s
t
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Speed vs. Velocity

• Speed tells you how fast you are going.
• Ex. 40 mph
• Velocity tells you how fast you are going and in
  what direction you are going.
• Ex. 6 mph east

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Speed and Velocity can both be represented by v.
Distance traveled Time interval
Velocity
d

• d distance
• t time
• v speed / velocity

v
t
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Units for Speed or Velocity
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Average Speed vs. Instantaneous Speed

• Average speed is the total distance traveled
  divided by the total time.
• The speed at any one instant is called the
  instantaneous speed. This is the speed indicated
  by the vehicles speedometer.

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Ex. 1 Horse

• How fast is the horse running if he ran 11.25
  miles in 15 minutes?
• Hint 1 hour 60 minutes

v d t 11.25 mi 0.25 hr 45 mph
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Ex. 2 Airplane

• An airplane is flying at a constant speed of 150
  m/s. After one hour, how far has the plane
  traveled? Hint 1 hour 3600 seconds

d v x t 150 m/s x 3600 sec 540,000 m
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Position vs. Time Graph
C
B
A

• A) 60 mph B) 0 mph C) 60 mph
• Average speed 90 miles/ 2 hours 45 mph

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Whats happening in the pictures below?
Moving away from start.
Moving back toward start.
Stopped. (zero speed)
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Time distance for a car traveling at constant
speed
Speed Slope
Slope rise/run (20-10)/(4-2) 10/2 5
m/s
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Ex. 3 Determine speed from the slope of a graph.
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Acceleration is the rate at which an objects
speed changes.

• v velocity (m/s)
• v (v2- v1)
• t seconds (s)
• aavg acceleration (m/s2)

? v
a
t
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Ex. 4 Acceleration of an Airliner

• A pilot increases the takeoff speed of an
  airliner from 20 m/s to 200 m/s in 30 seconds.
  Find the magnitude of the average acceleration of
  the airliner.

a v/t (200-20) ? (30) 6 m/s2
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Acceleration Graphs

• A) speeding up B) slowing down
  C) constant speed
• (positive slope) (negative slope)
  (no slope)
• Deceleration

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Calculating acceleration from slope.
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Speed, Velocity, Acceleration Video