Concept explainers
(a)
To Find: The average
(a)
Answer to Problem 38P
Explanation of Solution
Given:
Initial angular speed of the fly wheel,
Final angular speed of the fly wheel
Time taken to pull the rope,
Time taken during spin up,
Time taken during spin down,
Formula used:
Calculation:
Average angular acceleration for spin up is:
Average angular acceleration for spin down is:
Conclusion:
Spin down acceleration
Spin up acceleration
(b)
To find: Maximum angular speed reached by fly wheel.
(b)
Answer to Problem 38P
Explanation of Solution
Given:
Initial angular speed of the fly wheel,
Final angular speed of the fly wheel
Formula used:
Where,
Calculation:
Substitute the given value in the equation,
Conclusion:
(c)
To find: The ratio of the number of revolutions made during spin-up to the number made during spin down.
(c)
Answer to Problem 38P
Explanation of Solution
Given:
Time taken to pull the rope,
Time taken during spin up,
Time taken during spin down,
Angular speed at spin up
Angular speed at spin down,
Angular acceleration for spin up,
Angular acceleration for spin up,
Formula used:
Number of revolutions can be obtained by:
Where,
Calculation:
For spin-up revolution:
For spin down revolution:
Divide equation (1) by equation (2)
Conclusion:
Ratio of the number of revolutions made during spin-up to the number made during spin down is
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Chapter 9 Solutions
Physics for Scientists and Engineers, Vol. 3
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