ASVAB Mechanical Comprehension Practice Test 118127 Results

Your Results Global Average
Questions 5 5
Correct 0 3.26
Score 0% 65%

Review

1

A wedge converts force applied to its blunt end into force __________ its inclined surface.

57% Answer Correctly

opposite to

parallel to

along

perpendicular to


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 If you lift a 17 lbs. rock 16 ft. from the ground, how much work have you done?
70% Answer Correctly
272 ft⋅lb
None of these is correct
544 ft⋅lb
0 ft⋅lb

Solution
Work is force times distance. In this case, the force is the weight of the rock so:
\( W = F \times d \)
\( W = 17 \times 16 \)
\( W = 272 \)

3

What type of load acts on a relatively small area of a structure?

75% Answer Correctly

dynamic load

impact load

concentrated load

non-uniformly distributed load


Solution

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.


4

When it comes to force, mass and acceleration have what kind of relationship?

66% Answer Correctly

inverse

exponential

logarithmic

linear


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 If the green box weighs 45 lbs. and is 5 ft. from the fulcrum, how far from the fulcrum would a 15 lbs. force need to be applied to balance the lever?
58% Answer Correctly
3.75 ft.
15 ft.
5 ft.
225 ft.

Solution

To balance this lever the torques at the green box and the blue arrow must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

Rada = Rbdb

where a represents the green box and b the blue arrow, R is resistance (weight/force) and d is the distance from the fulcrum.

Solving for db, our missing value, and plugging in our variables yields:

db = \( \frac{R_ad_a}{R_b} \) = \( \frac{45 lbs. \times 5 ft.}{15 lbs.} \) = \( \frac{225 ft⋅lb}{15 lbs.} \) = 15 ft.