ASVAB ASVAB Certifications ASVAB-SECTION-3 Questions & Answers

• Question 101:

  Forces existing in pairs are sometimes called __________.

  A. action and interaction

  B. reaction and interaction

  C. action and reaction

  D. friction and gravity

  Correct Answer: C

  A force cannot be exerted unless there is something there to push back. Forces exist in pairs. For every action there is a reaction.

• Question 102:

  The rate at which work is done is called __________.

  A. Power

  B. Effort

  C. Watts

  D. Horsepower

  Correct Answer: A

  The English unit of power is foot pound per second. It takes 550 foot pounds to make 1 horsepower.

  The SI unit is the joule per second or watt. A horsepower is 746 watts.

  The rate at which work is done is called power. Power is work done per unit of time.

• Question 103:

  Presume that Pulley C is rotating clockwise.

  What direction will Pulley A rotate?

  

  A. Clockwise

  B. Counterclockwise

  C. Insufficient information to answer

  D. Pulley A will not rotate

  Correct Answer: A

  By rotating clockwise. Pulley C will cause Pulley B to rotate counterclockwise, which will in turn cause Pulley A to rotate clockwise.

• Question 104:

  If you drag a log across the road, one way to reduce the amount of force needed to pull it would be to ___________.

  

  A. use a thicker rope

  B. pull harder

  C. cross at an angle

  D. lubricate the road

  Correct Answer: D

  If you drag a log across the road, one way to reduce the amount of force needed to pull it would be to

  lubricate the road.

  Two things contribute to the force needed to pull the log across the road: the weight (mass) of the log itself,

  and the friction between the log and the road.

  Lubricating the road will reduce the friction and therefore reduce the force needed to pull the log across the

  road.

• Question 105:

  If you want to hammer in a heavy nail, it might be a good idea to use a hammer with a __________.

  A. lighter head

  B. heavy head

  C. longer handle

  D. shorter handle

  Correct Answer: C

  A longer handle – a longer lever – allows the hammerhead to reach a higher speed, thereby producing more striking force.

• Question 106:

  Which of the following is not a simple machine?

  A. Lever

  B. Inclined plane

  C. Axe

  D. Pulley

  Correct Answer: C

  An axe is a compound machine: the handle is a lever, and the head is two inclined planes (each side of the blade edge).

• Question 107:

  An above-ground suburban water tank holds 540 gallons of water when full.

  If the tank starts out full and is drained at a rate of 60 gallons per minute, how many seconds will it take to empty out halfway?

  A. 54

  B. 240

  C. 270

  D. 480

  Correct Answer: C

  540 gallons divided by 60 gallons a minute means that it takes nine minutes to drain the tank completely.

  Half of that time is 4.5 minutes; 4.5 multiplied by 60 seconds equals 270 seconds.

• Question 108:

  How can a gear system derive the greatest amount of mechanical advantage when a seven-tooth gear drives a ___________?

  A. 29-tooth gear

  B. 5-toothgear

  C. 24-tooth gear

  D. 17-tooth gear

  Correct Answer: A

  The greater the difference between the number of teeth of the two meshed gears, the greater the torque or mechanical advantage.

• Question 109:

  In the diagram in question 4, if the wheel on the left turns clockwise, which way will the wheel on the right turn?

  A. Clockwise

  B. Counterclockwise

  C. Counter-counterclockwise

  D. Unable to tell from the information given

  Correct Answer: B

  If the wheel on the left turns clockwise, the wheel on the right will turn counterclockwise.

• Question 110:

  The wheels below are connected by a belt as shown.

  If the larger wheel makes two revolutions, how many revolutions will the smaller wheel make?

  

  A. Less than one

  B. One

  C. Two

  D. More than two

  Correct Answer: D

  We are not told the sizes of the two wheels, but we can see that one is larger than the other.

  If the two wheels are connected by a belt, the small wheel will be forced to turn fester and complete more

  turns than the larger wheel.