ASVAB ASVAB Certifications ASVAB-SECTION-3 Questions & Answers

• Question 1:

  In the figure below, if gear A turns 15 times, how many revolutions will gear B make?

  

  A. 15 revolutions

  B. 5 revolutions

  C. 30 revolutions

  D. 45 revolutions

  Correct Answer: D

  Gear A has 18 teeth and gear B has 6 teeth. Therefore, for every 1 revolution of gear A, gear B will have 3 revolutions.

• Question 2:

  When a football is thrown upwards in the air, what causes it to arc back towards the ground?

  A. Centrifugal force

  B. Gravity

  C. Friction

  D. Wind resistance

  Correct Answer: B

  Gravity is the force that causes objects to be pulled back towards the earth.

• Question 3:

  An axe is an example of what type of simple machine.

  A. Lever

  B. Inclined plane

  C. Wedge

  D. None of the above

  Correct Answer: C

  An axe is a classic example of a wedge.

• Question 4:

  On a bicycle there are 30 teeth on the gear sprocket connected to the pedals, and 10 teeth on the sprocket connected to the rear wheels.

  If you pedal the bike 12 times, how many times will the rear wheel turn?

  A. 4 times

  B. 12 times

  C. 24 times

  D. 36 times

  Correct Answer: D

  Since there are 30 teeth on the pedal sprocket, but only 10 teeth on the rear wheel, each revolution of the

  pedal will turn the rear wheel 3 times.

  So 12 revolutions will turn the rear wheel 36 times.

• Question 5:

  The diagram below represents a load sliding down an incline. Which of the forces (A,B,C, or D) represent friction?

  

  A. A

  B. B

  C. C

  D. D

  Correct Answer: D

  Friction is represented by the force the resists the load moving down the hill.

• Question 6:

  What weight (X) is needed to balance the two loads shown in the figure below?

  

  A. 15 lbs

  B. 10 lbs

  C. 5 lbs

  D. 7.5 lbs

  Correct Answer: B

  For the weights to balance, the sum of the forces must balance.

  Therefore, (5 lbs × 8 ft) + (10 lbs × 4 ft) = X lbs × 8 ft or 40 lb-ft + 40 lb-ft = 8X lb-ft or X=10 lbs

• Question 7:

  Which of the following is not a type of simple machine?

  A. Pulley

  B. Spring

  C. Lever

  D. Screw

  Correct Answer: B

  The six types of simple machines are: pulley, lever, screw, wheel and axle, wedge, inclined plane.

• Question 8:

  In the pulley system below, how fast does pulley D rotate, if pulley A rotates at 100 rpm?

  

  A. 25 rpm

  B. 50 rpm

  C. 100 rpm

  D. 12.5 rpm

  Correct Answer: D

  A larger pulley causes a smaller pulley to rotate faster by the ratio of their diameters.

  If pulley A rotates at 100 rpm, then pulley B rotates at 100 × 4/10 = 40 rpm. Since C is directly connected

  to B it rotates at the same rate (40 rpm).

  Finally, pulley D will rotate at 40 rpm × 5/16 = 12.5 rpm

• Question 9:

  

  Which of the following is an example of a Class 2 Lever?

  A. Fishing rod

  B. Bottle opener

  C. See-Saw

  D. Scissors

  Correct Answer: B

  A bottle opener is a single class 2 lever.

  A see-saw and scissors are class 1 levers.

  A Fishing rod is a class 3 lever.

• Question 10:

  In the pulley system below, how fast does pulley D rotate, if pulley A rotates at 50 rpm?

  

  A. 100 rpm

  B. 50 rpm

  C. 200 rpm

  D. 64 rpm

  Correct Answer: C

  A larger pulley causes a smaller pulley to rotate faster by the ratio of their diameters.

  If pulley A rotates at 50 rpm, then pulley B rotates at 50 × 8/5=80 rpm. Since C is directly connected to B it

  rotates at the same rate (80 rpm).

  Finally, pulley D will rotate at 80 rpm x 10/4 = 200 rpm