Concept explainers
(a)
To identify about who will suffer more transverse break in a bone in human or a cow.
Answer to Problem 78QAP
The human suffers more transverse break in a bone than a cow
Explanation of Solution
Given:
Ultimate stress in the transverse direction for human bone
Ultimate stress in the transverse direction for cow bone
Formula used:
Here, all alphabets are in their usual meanings.
Calculation:
Since,
Here, human has less area of the cross-section than cow and their ultimate stresses in the transverse direction are nearly equal as compare to their area of the cross-sections.
Hence, human suffers more transverse break in a bone than a cow
Conclusion:
Thus, the human suffers more transverse break in a bone than a cow.
(b)
To explain, how cow's bones are much more capable of supporting their extreme weight than human.
Answer to Problem 78QAP
The cow's bones are much more capable of supporting their extreme weight than human because of high longitudinal ultimate stress and wider bone.
Explanation of Solution
Given:
Longitudinal yield stress for human bone
Longitudinal ultimate stress for human bone
Longitudinal yield stress for cow bone
Longitudinal ultimate stress for cow bone
Formula used:
Here, all alphabets are in their usual meanings.
Calculation:
Since,
Here, cow has more area of the cross-section and wider bone (or thicker) than man but longitudinal ultimate stress for cow bone
Hence, the cow's bones are much more capable of supporting their extreme weight than human.
Conclusion:
Thus, the cow's bones are much more capable of supporting their extreme weight than human because of high longitudinal ultimate stress and wider bone.
(c)
The compressive force before the breaking the bone.
Compressed length of the bone.
Answer to Problem 78QAP
The compressive force before the breaking the bone is
Compressed length of the bone is
Explanation of Solution
Given:
Compressive ultimate stress for human bone
Longitudinal elastic modulus of human bone
Area of cross-section of woman's leg
Length of bone
Let
Formula used:
Longitudinal elastic modulus
Here, all alphabets are in their usual meanings.
Calculation:
Substituting the given values in above formula,
Now, using equation (ii),
Hence, the compressive force before the breaking the bone is
Compressed length of the bone is
Conclusion:
Thus, the compressive force before the breaking the bone is
Compressed length of the bone is
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Chapter 9 Solutions
COLLEGE PHYSICS
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