ASVAB Mechanical Comprehension Practice Test 508544 Results

Your Results Global Average
Questions 5 5
Correct 0 3.47
Score 0% 69%

Review

1

Coplanar forces:

62% Answer Correctly

act along the same line of action

have opposite dimensions

pass through a common point

act in a common plane
Solution

Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

2

Which of the following surfaces would have the lowest coefficient of friction?

86% Answer Correctly

leather

tile

ice

concrete
Solution

Coefficient of friction (μ) represents how much two materials resist sliding across each other.  Smooth surfaces like ice have low coefficients of friction while rough surfaces like concrete have high μ.

3

Friction resists movement in a direction __________ to the movement.

82% Answer Correctly

normal

opposite

parallel

perpendicular
Solution

Friction resists movement. Kinetic (also called sliding or dynamic) friction resists movement in a direction opposite to the movement. Because it opposes movement, kinetic friction will eventually bring an object to a stop. An example is a rock that's sliding across ice.

4 If the handles of a wheelbarrow are 2.0 ft. from the wheel axle, how many pounds of force must you exert to lift the handles if it's carrying a 160 lbs. load concentrated at a point 0.5 ft. from the axle?
52% Answer Correctly
276
40
53.1
56
Solution
This problem describes a second-class lever and, for a second class lever, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance: Fede = Frdr. In this problem we're looking for effort force:
\( F_e = \frac{F_r d_r}{d_e} \)
\( F_e = \frac{160 \times 0.5}{2.0} \)
\( F_e = \frac{80.0}{2.0} \)
\( F_e = 40 \)
5

The work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. This defines which of the following?

61% Answer Correctly

Pascal's law

conservation of mechanical energy

work-energy theorem

mechanical advantage
Solution

The work-energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Simply put, work imparts kinetic energy to the matter upon which the work is being done.