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Section 2.5 Motion with Constant Acceleration © 2015 Pearson Education, Inc.
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Section 2.5 Motion with Constant Acceleration
© 2015 Pearson Education, Inc.
Constant Acceleration Equations• First equation
© 2015 Pearson Education, Inc.
Constant Acceleration Equations
• Derivation of the second equation: Displacement as a function of time
© 2015 Pearson Education, Inc.
The displacement during a time interval is the area under the velocity-time graph
© 2015 Pearson Education, Inc.
Second Constant Acceleration Equation
© 2015 Pearson Education, Inc.
What is the equation for this graph?
© 2015 Pearson Education, Inc.
© 2015 Pearson Education, Inc.
Text: p. 44
Third Constant Acceleration Equation
• Combining both equations gives us a relationship between displacement and velocity:
© 2015 Pearson Education, Inc.
For motion with constant acceleration:
– Velocity changes steadily:
– The position changes as the square of the time interval:
– The change in velocity in terms of displacement, not time:
© 2015 Pearson Education, Inc.
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Example
As you drive in your car at 15 m/s you see a child’s ball roll into the street ahead of you. You hit the brakes and stop as quickly as you can. Your reaction time is 0.45 sec. Once you hit the brakes you come to rest in 1.5 s. How far does your car travel from the time you see the ball?
© 2015 Pearson Education, Inc.
As you drive in your car at 15 m/s you see a child’s ball roll into the street ahead of you. You hit the brakes and stop as quickly as you can. Your reaction time is .45sec. Once you hit the brakes you come to rest in 1.5 s. How far does your car travel from the time you see the ball? DRAW A PARTICLE MODEL AND A GRAPH TO REPRESENT THE MOTION
© 2015 Pearson Education, Inc.
SOLVE
© 2015 Pearson Education, Inc.
