ASVAB Mechanical Comprehension Practice Test 322901 Results

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

Review

1 A 390 lb. barrel is rolled up a 12 ft. ramp to a platform that's 3 ft. tall. What effort is required to move the barrel?

53% Answer Correctly

	87.8 lbs.
	97.5 lbs.
	93.5 lbs.
	99 lbs.

Solution

This problem describes an inclined plane and, for an inclined plane, the effort force multiplied by the effort distance equals the resistance force multipied by the resistance distance:

F_ed_e = F_rd_r

Plugging in the variables from this problem yields:

F_e x 12 ft. = 390 lbs. x 3 ft.
F_e = \( \frac{1170 ft⋅lb}{12 ft.} \) = 97.5 lbs.

Sam can do 50 ft. lb. of work in 2 minutes and 5 seconds. What would Sam have to do to increase his power output?

64% Answer Correctly

	do the work in 3 minutes
	do the work in 2 minutes
	do 25 ft. lb. of work in 2 minutes 5 seconds
	do 100 ft. lb. of work in 4 minutes 12 seconds

Solution

Power is the rate of doing work or \(\frac{W}{t}\). To increase power, increase the work being done in the same amount of time or do the same amount of work in less time.

3 How much work can a 1 hp engine do in 2 seconds?

52% Answer Correctly

	2 ft⋅lb
	1100 ft⋅lb
	4 ft⋅lb
	0 ft⋅lb

Solution

Horsepower (hp) is a common measure of power output for complex machines. By definition, a 1 hp machine does 550 ft⋅lb of work in 1 second: 1 hp = 550 ft⋅lb/s. Substituting the variables for this problem gives us:
\( W = 1 hp \times 550 \frac{ft⋅lb}{s} \times 2s = 1100 ft⋅lb \)

On Earth, acceleration due to gravity (g) is approximately __________.

81% Answer Correctly

	6.67 x 10^-11 m/s²
	1 m/s
	1 m/s²
	9.8 m/s²

Solution

Newton's Law of Univeral Gravitation defines the general formula for the attraction of gravity between two objects: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) . In the specific case of an object falling toward Earth, the acceleration due to gravity (g) is approximately 9.8 m/s².

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

66% Answer Correctly

	inverse
	linear
	logarithmic
	exponential

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.