1. Acceleration
Ch. 10.2

2. Objectives
Describe the concept of acceleration as a change in velocity.
Explain why circular motion is continuous acceleration even when the speed does not change.
Calculate acceleration as the rate at which velocity changes.
Graph acceleration on a velocity-time graph.

3. This Graph Shows Constant Velocity2.
Constant
Increasing
No Velocity 1. 3.
Answer Now 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

4. This Graph Shows No Velocity1.
Constant
No Velocity
Increasing 2. 3.
Answer Now 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

5. What is the distance a man can run in 1 hour if he runs at 7 mi/hr?
7 km
7 m
7 mi
Answer Now 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

6. What is the Velocity of a Plane that Travels 500 mi in 1 hour
500m/s
500 mi/hr
500 km/hr
Answer Now 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

7. Using the Conservation of Momentum if car has the momentum of 50 kg
Using the Conservation of Momentum if car has the momentum of 50 kg*m/s and a man is in the moving car the man has?
50 m/s
50 kg
50 kg * m/s
Answer Now 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

8. final velocity – initial velocity
Acceleration
Acceleration = change in velocity divided by the time interval in which the change occurred.
Acceleration =
a =
final velocity – initial velocity
time
vf – vi t

9. Units
Acceleration = Vf – V i t
Units = m or m
s s * s

10. Acceleration Acceleration = rate at which velocity changes over time
Quick time movie acceleration
Acceleration occurs when there's a change in
Speed
Direction
Or both change

11. Uniform circular motion is constant acceleration.
QT Centripetal Acceleration
Video of bucket and water having centripetal acceleration

12. Acceleration Acceleration can be determined from a graph
QT Graphical Representations of Accelerations

13. Acceleration can also be determined from a velocity-time graph
A straight line with slope = constant acceleration
Slope of the line = acceleration

14. Horizontal line = constant speed, no acceleration or deceleration.

15. Examine the following graph.

16. A negative slope indicates that an object is slowing down or decelerating.

17. Calculating Acceleration
Acceleration is the rate at which velocity changes.
Acceleration Equation (for straight-line motion)
QT Distinguishing B/W Velocity and Acceleration
QT Average Acceleration
SI Units = m/s2

18. The Top Thrill Dragster at Cedar Point goes from 0 m/s to 53
The Top Thrill Dragster at Cedar Point goes from 0 m/s to 53.6 m/s (120 mph) in 4 seconds. What is its acceleration?
Given:
a =
Vf =
V i =
t =
Algebra:
Substitution:

19. A car traveling home at a velocity of 15
A car traveling home at a velocity of 15.6 m/s slams on its brakes and comes to a stop to avoid a dog. If it takes 5 seconds to stop, what is the cars acceleration?
Given:
a =
Vf =
V i =
t =
Algebra:
Substitution:

20. In what direction is the car accelerating?
How can you tell mathematically?

21. A Porsche Boxster has an acceleration of 4. 51 m/s2
A Porsche Boxster has an acceleration of 4.51 m/s2. If the car starts from rest how much time would it take for the vehicle to reach a speed of 11.3 m/s?
Given:
a =
Vf =
V i =
t =
Algebra:
Substitution:

22. A golf ball thrown from the top of the sears tower accelerates at 9
A golf ball thrown from the top of the sears tower accelerates at 9.8 m/s2 toward the ground and lands on the pavement 9.2 seconds. If the ball’s final speed is 93.0 m/s what was the speed with which the ball was initial thrown?
Algebra:
Substitution:
Given:
a =
Vf =
V i =
t =