ASVAB Mechanical Comprehension Practice Test 56927 Results

Your Results Global Average
Questions 5 5
Correct 0 3.25
Score 0% 65%

Review

1

Which of these will have the most impact on the kinetic energy of an object?

54% Answer Correctly

its speed

its direction

its weight

its mass


Solution

Kinetic energy is the energy of movement and is a function of the mass of an object and its speed: \(KE = {1 \over 2}mv^2\) where m is mass in kilograms, v is speed in meters per second, and KE is in joules. The most impactful quantity to kinetic energy is velocity as an increase in mass increases KE linearly while an increase in speed increases KE exponentially.


2

The force amplification achieved by using a tool, mechanical device or machine system is called:

80% Answer Correctly

work

power

mechanical advantage

efficiency


Solution

Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. Such a device utilizes input force and trades off forces against movement to amplify and/or change its direction.


3 How much resistance could a 170 lb. effort force lift using a block and tackle pulley that has 6 ropes supporting the resistance?
80% Answer Correctly
3060 lbs.
1020 lbs.
2040 lbs.
340 lbs.

Solution

The mechanical advantage (MA) of a block and tackle pulley is equal to the number of times the effort force changes direction. An easy way to count how many times the effort force changes direction is to count the number of ropes that support the resistance which, in this problem, is 6. With a MA of 6, a 170 lbs. effort force could lift 170 lbs. x 6 = 1020 lbs. resistance.


4

Which of these is the formula for force?

76% Answer Correctly

F = am2

F = m/a

F = a/m

F = ma


Solution

Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.


5

What's the last gear in a gear train called?

38% Answer Correctly

output gear

driven gear

driver gear

idler gear


Solution

A gear train is two or more gears linked together. Gear trains are designed to increase or reduce the speed or torque outpout of a rotating system or change the direction of its output. The first gear in the chain is called the driver and the last gear in the chain the driven gear with the gears between them called idler gears.