A hydraulic press features a 10 cm diameter ram and a 1 cm diameter plunger; lifting a 10-ton load on the ram requires a plunger force of _____________ kg?
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Answer: B. 100
Explanation
According to Pascal's law, pressure applied to an enclosed fluid is transmitted undiminished in all directions. Equating the pressure on the plunger to the pressure on the ram means force is proportional to area. Since the ram area is one hundred times larger than the plunger area, lifting a ten-ton load requires a plunger force of one hundred kilograms. Pascal's law forms the underlying physical principle governing hydraulic presses, brakes, and lifting jacks. Pressure is defined as force divided by cross-sectional area, meaning area ratios provide mechanical advantage. A ten-ton load equals ten thousand kilograms, which when divided by the one hundred to one area ratio gives one hundred kilograms.
A plunger force of ten kilograms neglects the area ratio multiplication factor inherent in hydraulic mechanical advantage. A force of one thousand kilograms overestimates the required input force by a factor of ten. A force of ten thousand kilograms equals the entire load weight, completely ignoring the hydraulic advantage of the smaller plunger.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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