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A
100 lbs
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B
1000 lbs
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C
10 lbs
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D
200 lbs
Why this is the answer
Pascal's principle: pressure applied to a confined fluid is transmitted equally throughout the fluid. Pressure = Force / Area. In a hydraulic system, pressure is the same in both pistons; force differs based on area. P = F/A is constant: F₁/A₁ = F₂/A₂. Calculation: F₁/A₁ = 100/2 = 50 psi. F₂ = P × A₂ = 50 × 20 = 1000 lbs. The larger piston multiplies force by the area ratio (10:1 in this case). Trade-off: distance moved is reduced by the same ratio. If small piston moves 10 inches, large piston moves 1 inch (volume is conserved: A₁ × d₁ = A₂ × d₂). Work in = work out (ignoring friction): 100 lbs × 10 in = 1000 lbs × 1 in = 1000 in-lbs. Real-world applications: hydraulic brakes (small force at pedal → large force at brake pad), hydraulic lifts (small pump pressure → lift heavy vehicles), hydraulic presses, excavator arms. Mechanical advantage of hydraulic system = A₂/A₁ (area ratio). Pneumatic systems work similarly but with compressed gas (less common in ASVAB). Fluid properties relevant to ASVAB MC: density, pressure increases with depth (P = ρgh in a fluid column), buoyancy (Archimedes' principle: buoyant force = weight of fluid displaced), incompressibility of liquids (vs compressibility of gases).
Source: ASVAB MC, Hydraulics