Concept explainers
(a)
The speed and magnitude of the acceleration of a person standing on the equator.
(a)
Answer to Problem 67P
A person standing on the equator has a speed
Explanation of Solution
Given:
Time taken by the Earth to rotate once on its axis,
Radius of the Earth,
Formula used:
The speed
The person on the equator experiences a centripetal acceleration
The total acceleration at the equator is given by,
Calculation:
A person standing on the equator, revolves in a circular path of radius
Calculate speed
All particles fixed on the Earth experience a centripetal force directed towards the center of its circular path. Hence it would experience a centripetal acceleration towards the center of its circular path.
Calculate the centripetal acceleration
Express the acceleration as a percentage of
The total acceleration experienced by the person is given by equation (3).
Conclusion:
Thus, a person standing on the equator has a speed
(b)
The direction of the acceleration vector of the person on the equator.
(b)
Answer to Problem 67P
The acceleration vector of the person is directed towards the center of the Earth.
Explanation of Solution
Introduction:
A person on the surface of the Earth experiences two forces-(i) Gravitational force
An object in order to move in a circular path requires
Figure 1
However, the weight, as felt by the person on the surface of the earth, is equal to the Normal force he experiences.
Hence, the acceleration
Conclusion:
Thus, the acceleration vector of the person on the Equator is directed towards the center of the Earth.
(c)
The speed and magnitude of the acceleration of a person standing at
(c)
Answer to Problem 67P
The speed of the person at
Explanation of Solution
Given:
The latitude where the person was standing,
Radius of the earth at equator,
The speed of the person at equator,
The centripetal acceleration at the equator,
Formula used:
The person at
The speed of person at
His speed at equator is given by
From equations (4) and (5),
The centripetal acceleration at the equator is given by the expression,
The centripetal acceleration at
From equations (4) and (5),
The person also experiences acceleration
The magnitude of the resultant acceleration is determined by using parallelogram law of vectors.
Calculation:
The motion of the person at
Figure 2
From Figure 2, it can be seen that
Use equation (11) in equation (6).
Substitute the value of the variables in the above equation.
Use equation (11) in equation (9) and substitute the values of the variables to calculate the value of
The vector
Substitute the values of variables in equation (10) and calculate the magnitude of the resultant acceleration
Conclusion:
Thus, the speed of the person at
(d)
The angle between the direction of the acceleration at
(d)
Answer to Problem 67P
The angle between the direction of the acceleration at
Explanation of Solution
Given:
The magnitude of centripetal acceleration at
The value of acceleration of free fall,
The latitude where the person was standing,
Formula used:
The direction of the acceleration at the equator is along the horizontal direction parallel to the direction of the centripetal acceleration at
Hence the angle
The vector diagram representing the accelerations is shown below:
Figure 3
This is given by
Calculation:
Substitute the values of the variables in equation (12).
Conclusion:
Thus, the angle between the direction of the acceleration at
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Chapter 3 Solutions
Physics for Scientists and Engineers
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- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning