ASVAB ASVAB Certifications ASVAB-SECTION-3 Questions & Answers

• Question 61:

  Which term below best describes the OPPOSITE of an increase in speed?

  A. rotation

  B. deceleration

  C. friction

  D. velocity

  Correct Answer: B

  Deceleration means slowing down.

• Question 62:

  A valve is used to perform which of the following functions?

  A. increase the temperature of a liquid

  B. control the flow of a liquid

  C. aid evaporation of a liquid

  D. decrease the density of a liquid

  Correct Answer: B

  Valves are placed in piping systems and can be opened or closed in order to control the flow of liquids or gasses.

• Question 63:

  Which principle of mechanical motion is used in the design of a roller coaster?

  A. momentum

  B. friction

  C. acceleration

  D. all of the above

  Correct Answer: D

  Acceleration must be considered in designing the maximum rise of the first hill.

  Momentum must be considered to ensure the train gets back to the starting point, since it has no motor.

  Friction must be considered in the design of the braking system.

• Question 64:

  A block of steel has a density of 0.29 pounds per cubic inch.

  If the block has dimensions of 1 inch by 1 inch by 3 inches, what is its weight?

  A. 0.29 pounds

  B. 0.58 pounds

  C. 0.87 pounds

  D. 1.0 pounds

  Correct Answer: C

  The volume of the block can be calculated by multiplying its length by its width by its height, or 1 times 1 times 3, which equals 2 cubic inches. The weight is the density multiplied by its volume, which is 3 cubic inches multiplied by 0.29 pounds per cubic inch, which equals 0.87 pounds.

• Question 65:

  Which mechanical components are typically used between a wheel and an axle to reduce friction?

  A. springs

  B. hinges

  C. bearings

  D. levers

  Correct Answer: C

  A set of bearings is typically a set of small metal balls packed in a groove and lubricated with grease or oil. The wheel rubs against one side of each ball, and the axle rubs against the other side. The net effect is that the wheel rolls much more easily.

• Question 66:

  The mechanical advantage of a winch is the ratio of the radius of the crank to the radius of the __________.

  A. arm

  B. lever

  C. fulcrum

  D. shaft

  Correct Answer: D

  The principle of a winch is not much different from that of a lever.

  Since the crank and the shaft turn together, the torque exerted by the effort (the force on the handle) must

  be equal to the torque exerted by the load (the tension in the rope). The mechanical advantage then is the

  ratio of the radius of the crank to the radius of the shaft.

• Question 67:

  The ideal mechanical advantage of a gear is the ratio of the number of teeth in the load gear to the number of teeth in the __________.

  A. effort gear

  B. loaded gear

  C. lifting gear

  D. spiral gear

  Correct Answer: A

  In mechanical devices, gears are used to change torque. The ideal mechanical advantage of a gear is the ratio of the number of teeth in the load gear to the number of teeth in the effort gear.

• Question 68:

  If Pulley A is the driver and turns counterclockwise, which pulley will turn the slowest?

  

  A. Pulley A

  B. Pulley B

  C. Pulley C

  D. Pulley D

  Correct Answer: D

  The pulley that is the largest will turn most slowly.

• Question 69:

  A screw consists of a single continuous spiral wrapped around a __________.

  A. piston

  B. cylinder

  C. helix

  D. square

  Correct Answer: B

  A screw is a simple device. It has been used for centuries as a means of lifting water out of wells and over the banks of irrigation canals. A screw consists of a single continuous spiral wrapped around a cylinder. The threads are cut into a rod in a spiral and make it possible to use the holding power of the screw in fastening objects together.

• Question 70:

  A ramp is a device commonly used to aid in __________.

  A. lifting

  B. lowering weights

  C. high-efficiency situations

  D. loading

  Correct Answer: A

  A ramp is a device commonly used to aid in lifting. The ramp is an inclined plane.

  The work output of an inclined plane is the work that would have to be done to lift the load directly. The

  work input is the actual force exerted in pushing the load up the ramp times the length of the ramp.

  An ideal mechanical advantage of an inclined plane is equal to its length divided by its height.