Free ASVAB Mechanical Comprehension Practice Test
The ASVAB Mechanical Comprehension Practice Test helps you practice the force, motion, machines, pressure, energy, and mechanical reasoning tested on the MC subtest.
You may see gears, pulleys, levers, ramps, fluids, moving objects, or simple diagrams and need to predict what happens next.
ASVAB Mechanical Comprehension Practice Test
Force Motion Friction and Newtons Laws
Which quantity must include both a size and a direction?
Velocity is a vector because it has both magnitude and direction. Mass, temperature, and time are scalar quantities.
Work Energy and Power
A worker pushes a crate with a 180 N force through 6 meters in the same direction as the force. How much work is done?
Work = force × distance. 180 × 6 = 1,080 joules.
Levers Torque Balance and Center of Gravity
Which simple machine is a wheelbarrow most commonly classified as?
In a second-class lever, the load is between the fulcrum and the effort. A wheelbarrow is the standard example.
Pulleys Mechanical Advantage and Efficiency
What is the main advantage of a single fixed pulley in an ideal system?
A fixed pulley mainly changes the direction of force. Its ideal mechanical advantage is 1.
Gears Wheel and Axle and Rotational Systems
A 12-tooth gear drives a 36-tooth gear. If the 12-tooth gear turns at 90 rpm, how fast does the 36-tooth gear turn?
Gear speed is inversely proportional to tooth count. 90 × 12/36 = 30 rpm.
Fluids Hydraulics Pneumatics and Pumps
A 120 N force acts on a hydraulic piston with an area of 6 cm². What pressure is applied to the fluid?
Pressure = force ÷ area. 120 ÷ 6 = 20 N/cm².
Simple Machines Inclined Planes Wedges and Screws
Two ramps reach the same height. One ramp is longer and less steep. Ignoring friction, what is the main advantage of the longer ramp?
An inclined plane trades force for distance.
Matter Springs Heat Structures and Mechanical Reasoning
Which property describes the amount of matter in an object?
Mass is the amount of matter in an object. Weight is the gravitational force acting on that mass.
Force Motion Friction and Newtons Laws
A skier is sliding straight down a snowy slope. In which direction does kinetic friction act on the skier?
Kinetic friction acts opposite the relative sliding motion. Since the skier slides downhill, friction acts uphill.
Work Energy and Power
A machine performs 2,400 joules of work in 8 seconds. What is its power output?
Power = work ÷ time. 2,400 ÷ 8 = 300 watts.
Levers Torque Balance and Center of Gravity
A 60 N force acts 2 meters from a lever's fulcrum. What force 4 meters from the fulcrum would balance it on the opposite side?
Balance requires equal torque. 60 × 2 = F × 4, so F = 30 N.
Pulleys Mechanical Advantage and Efficiency
In an ideal setup, one movable pulley is supported by two rope segments. How much input force is needed to lift a 400 N load?
Two supporting rope segments provide an ideal mechanical advantage of 2, so 400 ÷ 2 = 200 N.
Gears Wheel and Axle and Rotational Systems
Four external gears A, B, C, and D are arranged in a line, with each gear touching the next. If Gear A turns clockwise, which direction does Gear D turn?
Each external gear contact reverses direction. A clockwise makes B counterclockwise, C clockwise, and D counterclockwise.
Fluids Hydraulics Pneumatics and Pumps
A hydraulic system has a 2 cm² input piston and a 10 cm² output piston. If 100 N is applied to the input piston, what ideal output force is produced?
Pressure is 100 ÷ 2 = 50 N/cm². The same pressure on 10 cm² gives 500 N.
Simple Machines Inclined Planes Wedges and Screws
How is a wedge mechanically related to an inclined plane?
A wedge uses sloping surfaces like an inclined plane, but the wedge itself moves into the material.
Matter Springs Heat Structures and Mechanical Reasoning
A material has a mass of 600 grams and a volume of 200 cm³. What is its density?
Density = mass ÷ volume. 600 ÷ 200 = 3 g/cm³.
Force Motion Friction and Newtons Laws
A 12 kg cart is pushed by a net force of 60 N. What is its acceleration?
Use Newton's Second Law, F = ma. Acceleration = 60 ÷ 12 = 5 m/s².
Work Energy and Power
What is the kinetic energy of a 4 kg object moving at 6 m/s?
KE = 1/2 mv². One-half × 4 × 6² = 72 joules.
Levers Torque Balance and Center of Gravity
A mechanic applies a 50 N force perpendicular to a wrench 0.30 meters from the bolt. What torque is produced?
Torque = force × perpendicular distance. 50 × 0.30 = 15 N·m.
Pulleys Mechanical Advantage and Efficiency
A 600 N load is supported by three rope sections in an ideal pulley system. What input force is required?
Ideal mechanical advantage equals the number of supporting rope sections. 600 ÷ 3 = 200 N.
Gears Wheel and Axle and Rotational Systems
A round gear meshes with a straight toothed bar. What type of gear arrangement is this?
A rack-and-pinion system uses a round pinion gear and a straight toothed rack.
Fluids Hydraulics Pneumatics and Pumps
In an ideal hydraulic system, the output piston has five times the area of the input piston. If the output piston rises 2 cm, how far must the input piston move?
Fluid volume is conserved. If output area is five times larger, the input piston must move five times farther.
Simple Machines Inclined Planes Wedges and Screws
If a wedge is made longer while its maximum thickness stays the same, what generally happens to its ideal mechanical advantage?
A longer wedge with the same thickness has a gentler slope, increasing ideal mechanical advantage.
Matter Springs Heat Structures and Mechanical Reasoning
What type of energy is stored in a compressed spring?
A compressed or stretched spring stores elastic potential energy.
Force Motion Friction and Newtons Laws
Which statement best describes inertia?
Inertia is the tendency of an object to resist changes in its state of rest or motion.
Work Energy and Power
Using g ≈ 10 m/s², what gravitational potential energy does a 5 kg object have when it is 8 meters above the ground?
PE = mgh. 5 × 10 × 8 = 400 joules.
Levers Torque Balance and Center of Gravity
A crane extends its boom farther outward while carrying the same load. What happens to the combined center of gravity of the crane and load?
Moving the load farther outward shifts the combined center of gravity toward that load and can reduce stability.
Pulleys Mechanical Advantage and Efficiency
What is the minimum basic arrangement needed for a block-and-tackle system?
A basic block-and-tackle combines a fixed block and a moving block.
Gears Wheel and Axle and Rotational Systems
Two cone-shaped gears meet at approximately a right angle so rotation changes direction between shafts. What type of gears are they?
Bevel gears are commonly used to transmit rotary motion between intersecting shafts.
Fluids Hydraulics Pneumatics and Pumps
In a tank of the same liquid, which location has the greatest fluid pressure?
Hydrostatic pressure increases with depth.
Simple Machines Inclined Planes Wedges and Screws
A screw is best described mechanically as:
The thread of a screw is an inclined plane wrapped helically around a cylinder.
Matter Springs Heat Structures and Mechanical Reasoning
When two objects at different temperatures touch, heat naturally flows:
Thermal energy transfers from higher temperature to lower temperature.
Force Motion Friction and Newtons Laws
A 100 N weight hangs motionless from a single vertical rope. Ignoring the rope's weight, what is the tension in the rope?
Because the weight is motionless, the forces balance. The upward rope tension equals the 100 N downward weight.
Work Energy and Power
Ignoring air resistance, a ball is dropped from a height of 20 meters. Using g ≈ 10 m/s², what is its approximate speed just before it reaches the ground?
Using conservation of energy, v = √(2gh) = √(2 × 10 × 20) = 20 m/s.
Levers Torque Balance and Center of Gravity
An 80 lb child sits 2 feet from a seesaw pivot. Where should a 40 lb child sit on the opposite side to balance the seesaw?
Equal torque is required: 80 × 2 = 40 × d. Therefore d = 4 feet.
Pulleys Mechanical Advantage and Efficiency
An ideal pulley system has a mechanical advantage of 4. If the load rises 0.5 meter, approximately how far must the free end of the rope be pulled?
An ideal 4:1 system trades force for distance, so the input moves four times as far: 4 × 0.5 = 2 meters.
Gears Wheel and Axle and Rotational Systems
A wheel has a radius of 30 cm and is rigidly attached to an axle with a radius of 5 cm. What is the ideal mechanical advantage when effort is applied to the wheel?
Ideal mechanical advantage = wheel radius ÷ axle radius = 30 ÷ 5 = 6.
Fluids Hydraulics Pneumatics and Pumps
In a simple piston pump, pulling the piston so the chamber volume increases causes pressure inside the chamber to drop. Why can the intake valve then open?
A pressure difference lets higher outside pressure push fluid through the intake valve.
Simple Machines Inclined Planes Wedges and Screws
Mechanical advantage is most directly defined as:
Force mechanical advantage compares output force with input force.
Matter Springs Heat Structures and Mechanical Reasoning
Which shelf support arrangement generally resists downward loading best?
Triangular bracing provides a strong load path and resists shape change.
Force Motion Friction and Newtons Laws
Which statement correctly compares mass and weight?
Mass describes the amount of matter in an object. Weight is a force caused by gravity acting on that mass.
Work Energy and Power
Approximately how many watts are equal to 2.5 horsepower?
One horsepower is about 746 watts. 2.5 × 746 = 1,865 watts.
Levers Torque Balance and Center of Gravity
Which change generally makes a tall object harder to tip over?
A lower center of gravity and wider support base increase stability.
Pulleys Mechanical Advantage and Efficiency
A machine would require 100 N of input force if it were ideal, but friction makes the actual required force 125 N. What is its force efficiency compared with the ideal requirement?
Ideal input ÷ actual input × 100 = 100 ÷ 125 × 100 = 80%.
Gears Wheel and Axle and Rotational Systems
In an ideal gear-reduction system, increasing output torque is normally accompanied by:
Gear reduction trades rotational speed for torque.
Fluids Hydraulics Pneumatics and Pumps
An object floats at rest in water. What is true about the buoyant force on the object?
For an object floating at rest, upward buoyant force equals downward weight.
Simple Machines Inclined Planes Wedges and Screws
Why is the actual mechanical efficiency of a real simple machine less than 100%?
Real machines lose some useful mechanical energy to friction, heat, sound, and deformation.
Matter Springs Heat Structures and Mechanical Reasoning
Which property describes a material's ability to return toward its original shape after the deforming force is removed?
Elasticity is the ability of a material to recover its original shape after a load is removed, within its elastic limit.
MECHANICAL PRINCIPLES
What Mechanical Comprehension Tests
Mechanical Comprehension measures knowledge of mechanical and physical principles.
Strong preparation means understanding how force, motion, pressure, distance, and machine parts affect one another.
Force and Motion
Direction, friction, gravity, vectors, balance, and center of gravity.
Simple Machines
Levers, pulleys, gears, ramps, wedges, wheels, and mechanical advantage.
Energy and Power
Work, power, kinetic energy, potential energy, and horsepower.
Fluids and Structures
Pressure, hydraulics, pumps, support, and mechanical diagrams.
CURRENT TEST FORMAT
Mechanical Comprehension Test Format
The computer version gives more time per scored question than the paper version.
| Test Version | Questions | Time Limit | Approx. Time |
|---|---|---|---|
| CAT-ASVAB | Questions 15 scored | Time Limit 22 minutes | Approx. Time About 1 min 28 sec |
| Paper ASVAB | Questions 25 | Time Limit 19 minutes | Approx. Time About 46 sec |
The CAT-ASVAB may include unscored tryout questions. If they are added, extra time is also added to the subtest.
FORCE AND MOTION
Start by Finding What Can Move
Before solving a mechanical question, identify the object, the direction of force, and
what resists or changes the motion.
Force
A push or pull that can change speed, direction, or motion.
Friction
Acts against relative motion between contacting surfaces.
Gravity
Pulls mass downward and affects weight, balance, and potential energy.
Vector
A quantity that has both magnitude and direction.
TURNING EFFECT
Balance Depends on More Than Weight
A lever, seesaw, or beam balances according to both the force and its distance from the pivot. A smaller force placed farther from the fulcrum can balance a larger force placed closer to it.
Center of gravity matters too. A machine becomes less stable when the combined center of gravity moves toward or beyond the edge of its supporting base.
LEVERS
Find What Sits in the Middle
Lever class depends on the order of the fulcrum, effort, and load.
Fulcrum in the middle
A seesaw is a common example. The effort and load act on opposite sides of the pivot.
Load in the middle
A wheelbarrow is a common example and can provide a useful force advantage.
Effort in the middle
This arrangement often favors movement and speed rather than force multiplication.
PULLEYS
Count the Rope Sections Supporting the
Load
For pulley diagrams, supporting rope segments matter more than the number of pulley wheels you can see.
Fixed Pulley
Mainly changes the direction in which you pull.
Movable Pulley
Can reduce the force needed because more than one rope section supports the load.
Block and Tackle
Combines pulleys to increase mechanical advantage and trade force for pulling distance.
GEARS
Use Size, Teeth, and Contact Direction
When two external gears mesh, they rotate in opposite directions. A smaller gear also turns faster than a
larger gear when they remain meshed.
Spur gears
Straight teeth, usually on parallel shafts.
Bevel gears
Transfer rotation between shafts that meet at an angle.
Rack and pinion
Changes rotary motion into linear motion, or the reverse.
Worm and wheel
Can produce a large speed reduction and torque increase.
For ordinary external gears, every direct gear contact reverses the direction of rotation.
MECHANICAL ADVANTAGE
Less Force Usually Means More Distance
Simple machines do not create free energy. They change the way force and distance are exchanged.
Inclined Plane and Wedge
A longer, gentler ramp or wedge can reduce the force needed, but the input must move farther.
Wheel and Axle
Turning a larger wheel can create a stronger turning effect at the smaller axle.
CORE RELATIONSHIPS
Know the Few Formulas That Keep Appearing
The math is usually simple. The harder part is knowing which relationship matches the mechanical situation.
Work
Force multiplied by distance moved in the force direction.
Power
How quickly work is done.
Kinetic Energy
Energy an object has because it is moving.
Potential Energy
Stored gravitational energy due to height.
PRESSURE AND FLUIDS
Separate Pressure, Area, and Depth
Mechanical pressure questions can involve contact area, liquid depth, hydraulic pistons, or pumps.
Pressure and Area
Pressure equals force divided by area. The same force over a smaller area creates more pressure.
Pascal’s Principle
Pressure applied to a confined fluid is transmitted through the fluid. The same pressure acting on a larger piston area can create a larger force.
Fluid pressure also increases with depth, so a deeper point in a tank experiences more pressure than a point closer to the surface.
PUMPS
Follow Volume and Pressure Changes
If a piston increases the volume inside a chamber, pressure inside can fall. Higher outside pressure can then push fluid through an intake valve.
When reading a pump diagram, ask where volume changed, where pressure became higher or lower, and which valve can open.
STRUCTURAL SUPPORT
Support Questions Are About Where the Load Goes
Strong arrangements reduce unsupported distance and send loads into braces or supports efficiently. Triangular bracing and support placed closer to the load can reduce bending.
Do not choose a design simply because it uses more material. Look at where the force travels.
DIAGRAM METHOD
Read Mechanical Diagrams in Layers
A complicated picture becomes easier when you solve one mechanical relationship at a time.
1
Identify the machine
2
Find what can move
3
Find the force or load
4
Follow one relationship
5
Predict before choosing
MILITARY JOB SCORES
Mechanical Comprehension Is Not Part of the AFQT
The AFQT uses Arithmetic Reasoning, Mathematics Knowledge, Word Knowledge, and Paragraph Comprehension rather than Mechanical Comprehension.
MC can still appear in military service composite formulas used for mechanical, technical, and related occupations.
TEST PAGE
Use the Extra CAT Time Where It Helps
The standard CAT Mechanical Comprehension section gives about 1 minute 28 seconds per scored
question on average.
Quick recognition first
Simple gear direction or lever-class questions may take only a few seconds.
Slow down for diagrams
Pulley, hydraulic, balance, and structural questions may need more careful tracing.
Keep math simple
Most calculations use ratios, multiplication, division, force, distance, or basic energy relationships.
No calculator
Practice doing the common arithmetic cleanly by hand.
REVIEW MISTAKES
Review the Mechanical Principle Behind the Error
Do not memorize only the correct answer. Use the mistake to find the idea you need to understand better.
FAQs