ASVAB Mechanical Comprehension Practice Test 224273 Results

Your Results Global Average
Questions 5 5
Correct 0 3.70
Score 0% 74%

Review

1

A wedge is most similar to what other type of simple machine?

70% Answer Correctly

inclined plane

third-class lever

first-class lever

second-class lever


Solution

The wedge is a moving inclined plane that is used to lift, hold, or break apart an object. A wedge converts force applied to its blunt end into force perpendicular to its inclined surface. In contrast to a stationary plane where force is applied to the object being moved, with a wedge the object is stationary and the force is being applied to the plane. Examples of a wedge include knives and chisels.


2

Which of these is the formula for force?

77% Answer Correctly

F = a/m

F = am2

F = ma

F = m/a


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.


3

Two gears are connected and the larger gear drives the smaller gear. The speed of rotation will __________ and the torque will __________.

61% Answer Correctly

increase, decrease

decrease, decrease

increase, increase

decrease, increase


Solution

Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.


4

When all forces acting on a system cancel each other out, this is called:

80% Answer Correctly

rest

potential energy

equilibrium

stasis


Solution

When a system is stable or balanced (equilibrium) all forces acting on the system cancel each other out. In the case of torque, equilibrium means that the sum of the anticlockwise moments about a center of rotation equal the sum of the clockwise moments.


5 30 lbs. of effort is used by a machine to lift a 150 lbs. box. What is the mechanical advantage of the machine?
84% Answer Correctly
5
5.5
14
-3

Solution

Mechanical advantage is resistance force divided by effort force:

MA = \( \frac{F_r}{F_e} \) = \( \frac{150 lbs.}{30 lbs.} \) = 5