ASVAB Mechanical Comprehension Practice Test 927521 Results

	Your Results	Global Average
Questions	5	5
Correct	0	3.23
Score	0%	65%

Review

Friction resists movement in a direction __________ to the movement.

81% Answer Correctly

	perpendicular
	normal
	parallel
	opposite

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.

Assuming force applied remains constant, which of the following will result in more work being done?

53% Answer Correctly

	moving the object farther
	increasing the coefficient of friction
	moving the object with more speed
	moving the object with more acceleration

Solution

Work is accomplished when force is applied to an object: W = Fd where F is force in newtons (N) and d is distance in meters (m). Thus, the more force that must be applied to move an object, the more work is done and the farther an object is moved by exerting force, the more work is done.

3 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 130 lbs. load concentrated at a point 1.0 ft. from the axle?

52% Answer Correctly

	31.7
	65
	130
	260

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: F_ed_e = F_rd_r. In this problem we're looking for effort force:
\( F_e = \frac{F_r d_r}{d_e} \)
\( F_e = \frac{130 \times 1.0}{2.0} \)
\( F_e = \frac{130.0}{2.0} \)
\( F_e = 65 \)

Which of the following statements about drag is false?

58% Answer Correctly

	the amount of drag depends on the shape of an object
	the amount of drag depends on the speed of an object
	drag occurs during movement through a fluid
	slower objects experience more drag than faster objects

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.

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

74% Answer Correctly

	dynamic load
	concentrated load
	impact 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.