Concept explainers
A car travels on a straight, level road.
- (a) Starting from rest, the car is going 44 ft/s (30 mi/h) at the end of 5.0 s. What is the car’s average acceleration in ft/s2?
- (b) In 4.0 more seconds, the car is going 88 ft/s (60 mi/h). What is the car’s average acceleration for this time period?
- (c) The car then slows to 66 ft/s (45 mi/h) in 3.0 s. What is the average acceleration for this time period?
- (d) What is the overall average acceleration for the total time? (Note these convenient British unit conversions: 60 mi/h = 88 ft/s, 45 mi/h = 66 ft/s, and 30 mi/h = 44 ft/s.)
(a)
Answer to Problem 14E
Explanation of Solution
Given info: The initial velocity of the car is zero, final velocity of the car is
Explanation:
The formula for the acceleration is as follows,
Here,
Substitute
Conclusion:
Therefore, the average accleration of the car at the end of five seconds is
(b)
Answer to Problem 14E
Explanation of Solution
Given info: The final velocity of the car is
Explanation:
The final velocity at the end of
The formula for the acceleration is as follows,
Here,
Substitute
Conclusion:
Therefore, the average accleration of the car at the another four seconds is
(c)
Answer to Problem 14E
Explanation of Solution
Given info: The final velocity of the car is
Explanation:
The final velocity at the end of another four secondss is the initial velocity for this case.
The formula for the acceleration is as follows,
Here,
Substitute
Conclusion:
Therefore, the average accleration of the car at the another three seconds is
(d)
Answer to Problem 14E
Explanation of Solution
Given info: The final velocity of the car is
Explanation:
The final velocity of the car is
The total time
The formula for the acceleration is as follows,
Here,
Substitute
Conclusion:
Therefore, the overall average accleration of the car for the total time is
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Chapter 2 Solutions
An Introduction to Physical Science
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- An Introduction to Physical SciencePhysicsISBN:9781305079137Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar TorresPublisher:Cengage Learning