Concept explainers
(a)
The speed of the compressional wave.
(a)
Answer to Problem 59AP
The speed of the compressional wave is
Explanation of Solution
Write the expression for compressional wave.
Here,
Conclusion:
Substitute,
Therefore, the speed of the compressional wave is
(b)
The time taken by the back end of the rod to come to stop its motion.
(b)
Answer to Problem 59AP
The time taken by the back end of the rod to come to stop its motion is
Explanation of Solution
Write the expression for the time taken by the signal to stop to reach at the back end.
Here,
Conclusion:
Substitute,
Therefore, the time taken by the back end of the rod to come to stop its motion is
(c)
The distance moved by the back end of the rod at time
(c)
Answer to Problem 59AP
The distance moved by the back end of the rod at time
Explanation of Solution
Let the velocity with which the back end of the rod moving be
Write the equation for distance moved by the back end of the rod.
Conclusion:
Substitute,
Therefore, the distance moved by the back end of the rod at time
(d)
The strain of the rod.
(d)
Answer to Problem 59AP
The strain of the rod is
Explanation of Solution
Strain defined as the change in dimension by original dimension.
Write the expression for strain.
Here,
Conclusion:
Substitute,
Therefore, the strain of the rod is
(e)
The stress of the rod.
(e)
Answer to Problem 59AP
The stress of the rod is
Explanation of Solution
Young’s modulus is the ratio of stress by strain. From the known values of young’s modulus and strain, stress can be determined.
Write the expression for the stress of the rod.
Conclusion:
Substitute,
Therefore, the stress of the rod is
(f)
The maximum impact speed of the rod.
(f)
Answer to Problem 59AP
The maximum impact speed of the rod is
Explanation of Solution
The expression for the speed of the wave is.
Even if the front end strikes on wall, the back end will be in motion, and the time taken for the forward motion is.
Substitute equation (VI) in (VII).
The distance traveled at time
The strain of the rod is.
Substitute, equation (VIII) in (IX).
Substitute, equation (VIII) in (X).
The stress of the rod is.
Substitute, equation (XI) in (XII).
From equation (XIII) the expression for maximum speed, if the above stress is less than the yield stress is.
Conclusion:
Therefore, the maximum impact speed of the rod is
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Chapter 17 Solutions
Physics: for Science.. With Modern. -Update (Looseleaf)
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