ASVAB Mechanical Comprehension Practice Test 570531 Results

Your Results Global Average
Questions 5 5
Correct 0 3.53
Score 0% 71%

Review

1

A watt is the unit for which of the following?

71% Answer Correctly

energy

work

power

mechanical advantage


Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.


2

A a seesaw / teeter-totter is an example of which of the following?

69% Answer Correctly

second-class lever

inclined plane

first-class lever

third-class lever


Solution

A first-class lever is used to increase force or distance while changing the direction of the force. The lever pivots on a fulcrum and, when a force is applied to the lever at one side of the fulcrum, the other end moves in the opposite direction. The position of the fulcrum also defines the mechanical advantage of the lever. If the fulcrum is closer to the force being applied, the load can be moved a greater distance at the expense of requiring a greater input force. If the fulcrum is closer to the load, less force is required but the force must be applied over a longer distance. An example of a first-class lever is a seesaw / teeter-totter.


3

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.


4

One Horsepower (hp) is equal to how many watts?

76% Answer Correctly

746

1492

9.8

1


Solution

Power is the rate at which work is done, P = w/t, or work per unit time. The watt (W) is the unit for power and is equal to 1 joule (or newton-meter) per second. Horsepower (hp) is another familiar unit of power used primarily for rating internal combustion engines. 1 hp equals 746 watts.


5

A ramp is an example of which kind of simple machine?

84% Answer Correctly

none of these

first-class lever

inclined plane

wedge


Solution

An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.