ASVAB Mechanical Comprehension Practice Test 6

Question 1 easy

If an air-filled sealed container is taken from sea level and carried high up into the mountains, what change in its volume will most likely occur?

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Correct answer: C — The volume of the container will expand.

As altitude increases, atmospheric pressure decreases. According to Boyle's Law, as external pressure decreases, the air inside an elastic or flexible container expands, increasing its volume.

Question 2 medium

A team of movers applies a combined force of 625.5 newtons to slide a heavy safe across a tile floor. If they perform a total of 2,814.75 joules of work, how far did they move the safe?

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Correct answer: A — 4.5 meters

Work is calculated using the formula Work = Force × Distance. Rearranging to solve for distance: Distance = Work / Force = 2,814.75 joules / 625.5 newtons = 4.5 meters.

Question 3 easy

A forklift applies a force of 1,250 newtons to elevate a wooden pallet to a height of 24 meters. How much total work is performed by the forklift?

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Correct answer: D — 30,000 joules

Work = Force × Distance. Multiplying the force applied by the vertical distance moved gives: 1,250 newtons × 24 meters = 30,000 joules.

Question 4 easy

A crowbar is used as a class-1 lever to pry open a wooden crate. If the input effort arm measures 6 meters and the output load arm measures 2 meters, what is the mechanical advantage of the crowbar?

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Correct answer: B — 3

The ideal mechanical advantage (MA) of a lever is calculated by dividing the length of the input arm by the length of the output arm: MA = Input Arm / Output Arm = 6 meters / 2 meters = 3.

Question 5 medium

Which fundamental principles explain how hydraulic braking systems operate in heavy machinery?

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Correct answer: C — Both A and B.

Hydraulic systems rely on Pascal's Principle, which states that pressure applied to a confined fluid is transmitted equally in all directions. Additionally, fluids (liquids) are virtually incompressible, allowing force to transfer efficiently without compressing the fluid.

Question 6 medium

A gardener uses a pry bar to remove a boulder. The bar has an input effort arm measuring 4.5 meters and an output load arm measuring 0.5 meters. What is the mechanical advantage of this pry bar?

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Correct answer: D — 9

The mechanical advantage (MA) of a lever is determined by dividing the effort arm length by the load arm length: MA = Input Arm / Output Arm = 4.5 meters / 0.5 meters = 9.

Question 7 hard

An engineer crafts three solid spheres of identical aluminum alloy but with different diameters (2 cm, 5 cm, and 10 cm). If the smallest sphere sinks when placed in a container of liquid mercury, what will happen to the other two spheres when dropped into the same container?

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Correct answer: B — Both of the remaining spheres will also sink.

Buoyancy depends strictly on the relative density of the object and the fluid, not on the overall size or total mass of the object. Since all three spheres are composed of the exact same material, their density is constant. If the smallest sphere sinks, its density exceeds that of the liquid, meaning all three spheres will sink.

Question 8 medium

An electric winch operates at a power output of 62.5 watts to lift a load vertically over a period of 14.5 seconds. How much total mechanical work is done by the winch?

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Correct answer: C — 906.25 joules

Power is defined as the rate at which work is performed (Power = Work / Time). Rearranging the formula to solve for work gives Work = Power × Time = 62.5 watts × 14.5 seconds = 906.25 joules.

Question 9 hard

A heavy two-person beam scale remains horizontal and still when two packages are placed on opposite pans at equal distances from the central fulcrum. Which mechanical condition best describes this system?

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Correct answer: A — Rotational and translational equilibrium

When a balanced beam scale remains stationary, the net external force acting on it is zero (translational equilibrium) and the net torque about the fulcrum is zero (rotational equilibrium).

Question 10 medium

Which of the following mechanical devices relies primarily on a compressed spring to store mechanical potential energy and quickly release it to perform its primary function?

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Correct answer: D — A mechanical staple gun

A mechanical staple gun uses a heavy spring that is compressed as the handle is squeezed. When released, the elastic potential energy stored in the spring drives the staple into a surface.

Question 11 hard

A technician inspects a dial gauge mounted on a pressurized steam pipe. The dial face contains two concentric scales: an outer scale marked in 'psi' (pounds per square inch) and an inner scale marked in 'bar'. What specific physical quantity is this instrument measuring?

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Correct answer: B — Fluid pressure

Psi (pounds per square inch) and bar are standard units of measurement for pressure. A dual-scale gauge featuring psi and bar directly measures fluid or gas pressure within a system.

Question 12 hard

A maintenance worker exerts a continuous horizontal force of 85 newtons to push a heavy tool cart across a level factory floor over a distance of 140 meters. How much work is performed by the worker against resistance?

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Correct answer: C — 11,900 joules

Work is calculated using the formula Work = Force × Distance. Multiplying the horizontal force applied by the displacement gives Work = 85 newtons × 140 meters = 11,900 joules.