When an unsupported elastic bar of uniform cross-section experiences longitudinal impact from a rigid bob traveling at velocity v, a compressive wave of intensity sc propagates through it such that______________________?
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Answer: A. vpE
Explanation
The magnitude of the stress wave generated by longitudinal impact is proportional to impact velocity. It depends directly on the acoustic impedance product of mass density and elasticity modulus. Mathematical derivation confirms that stress wave intensity equals the product v times p times E. Longitudinal impact sends stress waves traveling down the length of an elastic bar. Modulus of elasticity measures a material's resistance to elastic deformation under load. Mass density relates the physical mass of the bar to its total volume dimensions.
Impact dynamics analysis helps engineers design protective structures to absorb high-speed blows. Pile driving operations rely on understanding stress wave propagation through long metal columns. Excessive impact velocities can exceed material yield strengths and cause permanent structural damage. Option B features incorrect radical terms that do not match the stress wave equation. Option C introduces a half factor and incorrect variables irrelevant to longitudinal impact stress. Option D lists unformatted symbols that fail to represent the correct acoustic impedance product.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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