ASVAB Mechanical Comprehension Practice Test 476997 Results

Your Results Global Average
Questions 5 5
Correct 0 3.39
Score 0% 68%

Review

1

Friction resists movement in a direction __________ to the movement.

81% Answer Correctly

perpendicular

parallel

opposite

normal
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.

2 If input effort is 900 ft⋅lb, what output effort will be produced by a machine with a mechanical advantage of 4?
79% Answer Correctly
225ft⋅lb
3600 ft⋅lb
0ft⋅lb
7200ft⋅lb
Solution
Mechanical advantage is the ratio of output force to input force and tells us by how many times a machine multiplies input effort. So, a machine with a mechanical advantage of 4 will multiply an input effort of 900 ft⋅lb by 4 to produce an output effort of 3600 ft⋅lb.
3 If the handles of a wheelbarrow are 1.5 ft. from the wheel axle and the load is concentrated at a point 1.5 ft. from the axle, how many pounds of load will a 170 lbs. force lift?
47% Answer Correctly
None of these is correct
70.9
75.6
170
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 resistance force:
\( F_r = \frac{F_e d_e}{d_r} \)
\( F_r = \frac{170 \times 1.5}{1.5} \)
\( F_r = \frac{255.0}{1.5} \)
\( F_r = 170 \)
4

Drag is a type of:

82% Answer Correctly

work

kinetic energy

friction

potential energy
Solution

Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.

5

Which of the following is not a modulus of elasticity?

47% Answer Correctly

bulk modulus

stretch modulus

stress modulus

shear modulus
Solution

The modulus of elasticity measures how much a material or structure will deflect under stress. Stretch modulus is longitudinal stretch (like stretching raw bread dough), shear modulus is longitudinal deflection (like the horizontal displacement of a stack of magzines when a heavy object is placed upon them), and bulk modulus is compression of volume (like the compression of a loaf of bread under a heavy can at the bottom of a grocery bag).