What are the approximate values of piston velocity and acceleration near the dead-center positions in a slider-crank mechanism________________?
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Answer: A. 0, and more than co2r
Explanation
At the dead-center positions of a slider-crank mechanism, piston velocity is zero. Simultaneously, piston acceleration reaches its maximum value, exceeding omega squared r. This kinematic behavior occurs because the piston reverses direction at stroke extremes. Dead centers occur when the crank and connecting rod align straight at top and bottom limits. Velocity must drop to zero momentarily before the slider reverses its linear travel direction. Acceleration peaks at these turnaround points due to rapid centripetal and inertia forces.
Internal combustion engine pistons experience maximum inertial stress at top and bottom dead centers. Engine designers reinforce connecting rods to withstand these extreme acceleration forces at high speeds. Vibration balancing in reciprocating engines accounts for peak piston accelerations during operation. Option B suggests acceleration is less than expected, ignoring peak kinematic equations. Option C claims both velocity and acceleration are zero, violating motion reversal principles. Option D assigns velocity a non-zero value, which contradicts the stationary turnaround point.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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