ASVAB Mechanical Comprehension Practice Test 394455 Results

Your Results Global Average
Questions 5 5
Correct 0 3.11
Score 0% 62%

Review

1

Connected gears of different numbers of teeth are used together to change which of the following charasteristics of the input force?

66% Answer Correctly

rotational direction

energy

force

torque


Solution

Connected gears of different numbers of teeth are used together to change the rotational speed and torque of the input force. If the smaller gear drives the larger gear, the speed of rotation will be reduced and the torque will increase. If the larger gear drives the smaller gear, the speed of rotation will increase and the torque will be reduced.


2

Collinear forces:

73% Answer Correctly

are unrelated to each other

pass through a common point

act in a common plane

act along the same line of action


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.


3 If a 50 lbs. weight is placed 5 ft. from the fulcrum at the blue arrow and the green box is 4 ft. from the fulcrum, how much would the green box have to weigh to balance the lever?
61% Answer Correctly
187.5 lbs.
62.5 lbs.
0 lbs.
20.83 lbs.

Solution

To balance this lever the torques on each side of the fulcrum must be equal. Torque is weight x distance from the fulcrum so the equation for equilibrium is:

Rada = Rbdb

where a represents the left side of the fulcrum and b the right, R is resistance (weight) and d is the distance from the fulcrum.

Solving for Ra, our missing value, and plugging in our variables yields:

Ra = \( \frac{R_bd_b}{d_a} \) = \( \frac{50 lbs. \times 5 ft.}{4 ft.} \) = \( \frac{250 ft⋅lb}{4 ft.} \) = 62.5 lbs.


4

Which of the following is not a characteristic of a ceramic?

61% Answer Correctly

low corrosive action

high melting point

chemically stable

low density


Solution

Ceramics are mixtures of metallic and nonmetallic elements that withstand exteme thermal, chemical, and pressure environments. They have a high melting point, low corrosive action, and are chemically stable. Examples include rock, sand, clay, glass, brick, and porcelain.


5

A truck is using a rope to pull a car. Tension in the rope is greatest in which of the following places?

50% Answer Correctly

tension is equal in all parts of the rope

near the car

near the truck

in the middle


Solution

Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.