ASVAB Mechanical Comprehension Practice Test 962088 Results

Your Results Global Average
Questions 5 5
Correct 0 3.45
Score 0% 69%

Review

1

What type of load creates different stresses at different locations on a structure?

60% Answer Correctly

impact load

static uniformly distributed load

non-uniformly distributed load

dynamic 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.

2

A block and tackle with four pulleys would have a mechanical advantage of:

79% Answer Correctly

4

0

1

2
Solution

Two or more pulleys used together constitute a block and tackle which, unlike a fixed pulley, does impart mechanical advantage as a function of the number of pulleys that make up the arrangement.  So, for example, a block and tackle with three pulleys would have a mechanical advantage of three.

3 What is the efficiency of a machine has work input of 170 ft⋅lb and work output of 42 ft⋅lb?
67% Answer Correctly
75%
50%
25%
0%
Solution
Due to friction, a machine will never be able to utilize 100% of its work input. A certain percentage of that input will be lost in overcoming friction within the machine. Effeciency is a measure of how much of a machine's work input can be turned into useful work output and is calculated by dividing work output by work input and multiplying the result by 100:
\( Efficiency = \frac{Work_{out}}{Work_{in}} \times 100 \) \( = \frac{42 ft⋅lb}{170 ft⋅lb} \times 100 \) \( = 25% \) %
4

What type of load is sudden and for a relatively short duration?

69% Answer Correctly

dynamic load

concentrated load

non-uniformly distributed load

impact 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.

5 If you lift a 14 lbs. rock 25 ft. from the ground, how much work have you done?
70% Answer Correctly
350 ft⋅lb
-11 ft⋅lb
0 ft⋅lb
39 ft⋅lb
Solution
Work is force times distance. In this case, the force is the weight of the rock so:
\( W = F \times d \)
\( W = 14 \times 25 \)
\( W = 350 \)