ASVAB Study GuideMechanical Comprehension Practice Test 2
Tap an answer to check it instantly and read the explanation. 11 questions: 3 easy, 4 medium and 4 hard.
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Question 1 easy
A worker uses a hand winch to lift a heavy crate. Applying an input force of 40 newtons produces an output force of 280 newtons at the lifting hook. What is the mechanical advantage of the winch system?
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Correct answer: A — 7
Mechanical Advantage is calculated as Output Force divided by Input Force: $$\frac{280\text{ N}}{40\text{ N}} = 7$$
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Question 2 easy
How is the mechanical advantage (MA) of a simple machine mathematically defined?
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Correct answer: C — output force divided by input force
Mechanical advantage represents the factor by which a machine multiplies the force put into it, defined as output force divided by input force.
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Question 3 easy
According to Newton's First Law of Motion, what condition must be met for a stationary object on a frictionless surface to change its state and start moving?
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Correct answer: D — It must be acted upon by an net unbalanced force.
Newton's First Law states that an object at rest remains at rest unless acted upon by a net external unbalanced force.
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Question 4 medium
A mechanic uses a 6-foot steel pry bar to lift a 600-pound engine block. He places the pivot (fulcrum) exactly 1 foot away from the engine block. Assuming the pry bar is horizontal and weightless, how much downward force must he apply to the far end of the bar?
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Correct answer: B — 120 pounds
Total bar length = 6 ft (72 in). Load arm = 1 ft (12 in), effort arm = 5 ft (60 in). Torque balance: Effort Force × 5 ft = 600 lbs × 1 ft => Effort Force = $$\frac{600}{5} = 120$$ lbs.
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Question 5 medium
Why does a fully loaded freight truck require significantly more force to accelerate from a complete stop than an empty pickup truck?
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Correct answer: A — The freight truck has greater mass and therefore greater inertia resisting changes in motion.
Inertia is directly proportional to mass. An object with greater mass has higher inertia, meaning it offers greater resistance to any change in its velocity.
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Question 6 medium
If an industrial coil spring has a spring constant (k) of 8 pounds per inch, how much force is required to stretch it by 15 inches?
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Correct answer: C — 120 pounds
According to Hooke's Law $$(F = k \times x)$$, force equals spring constant multiplied by extension: 8 lbs/in × 15 in = 120 pounds.
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Question 7 medium
Which general physical term describes any interaction—either a push or a pull—that tends to change the motion, velocity, or shape of an object?
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Correct answer: B — force
A force is defined in physics as any push or pull exerted on an object that causes or attempts to cause a change in its velocity or state of motion.
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Question 8 hard
What is the gravitational force of attraction that pulls two masses toward each other, proportional to their masses and inversely proportional to the square of the distance between them?
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Correct answer: A — gravity
Gravity is the fundamental force of attraction that pulls any two objects with mass toward one another.
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Question 9 hard
A hydraulic piston exerts a total downward force of 450 pounds evenly across a flat surface area of 18 square inches. What is the resulting pressure in PSI (pounds per square inch)?
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Correct answer: C — 25
Pressure is calculated as Force divided by Area ($$P = \frac{F}{A}$$): 450 lbs / 18 sq in = 25 PSI.
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Question 10 hard
The suspension spring on a heavy utility truck compresses by 4 inches when subjected to a vertical payload weight of 1,200 pounds. What is the spring constant of this suspension spring in pounds per inch?
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Correct answer: A — 300
The spring constant (k) is determined by dividing force by compression distance ($$k = \frac{F}{x}$$): 1,200 lbs / 4 inches = 300 pounds per inch.
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Question 11 hard
An operator uses a class-1 lever to lift a 540-pound container. The container is located 2 feet from the pivot point (fulcrum), while the operator applies force at a position 6 feet from the fulcrum on the opposite side. What effort force is needed to balance and lift the container?
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Correct answer: D — 180 pounds
Using torque balance ($$\text{Force}_{\text{effort}} \times \text{Distance}_{\text{effort}} = \text{Force}_{\text{load}} \times \text{Distance}_{\text{load}}$$): Effort × 6 ft = 540 lbs × 2 ft => Effort $$= \frac{1{,}080}{6} = 180$$ pounds.