ASVAB: Mechanical Comprehension

• A truck ramp is used for its mechanical advantage, if it's 18 meters long and 3 meters high, what is the mechanical advantage of this inclined plane?

  a.)4

  b.)8

  c.)6

  d.)10


  c.)6

  
  

  **MA=L/H

  MA=18/3

  MA=6
• On a incline plane, the length is 15 and the height is 5. What is the mechanical advantage?

  a.)7

  b.)20

  c.)18

  d.)3

  d.)3

  
  

  *MA=L/H

  MA=15/5

  MA=3
• A wedge is 14 inches in length, and the mechanical advantage is 7. What is the width of the tool?

  a.)8

  b.)2

  c.)9

  d.)5

  b.)2

  
  

  *MA=L/W

  7/14=W

  2=W
• What the mechanical advantage of a wedge were the length is 21 and the width is 3?

  a.)7

  b.)6

  c.)10

  d.)4


  a.)7

  
  

  *MA=l/W

  21/3=7
• A child uses 3.5N to throw a ball into the air about 2.3 meters, how much work has she achieved?

  a.)1.2 J

  b.)5.8 J

  c.)8.05 J

  d.)1.521 J

  c.)8.05 J

  
  

  multiply 3.52.3=8.05 J
• If a rock climber expended 660 newtons up a 30 meters cliff, how much work did he exert?

  a.)22 J

  b.)690 J

  c.)690 N

  d.)19,800 J

  d.)19,800 J

  
  

  multiply 66030=19,800 J
• You are hammering a nail through a piece of wood, you are making sure you are holding the hammer the right way by holding the bottom of the hammer to grip it correctly to the strike the nail. Which class of lever are you using?

  a.)First class

  b.)Second class

  c.)Third class


  c.)Third class
• Say you are at work and you are using a staple to staple paper together. You are holding the front part of the staple to staple to the papers together. Which class of lever are you using?

  a.)First class

  b.)Second class

  c.)Third class

  b.)Second class
• A man is trying to lift a large package. The package weighs 200lbs. If he exerts 80 lbs of force, will he be able to move the package upward?

  a.)Yes because he has double the strength to lift the package

  b.)Yes because he has the mechanical advantage to carry the package upward

  c.)No the man will not be able to lift the package upward with 80 lbs of force

  d.)No there is not enough information to know what the man is using to lift the package

  c.)No the man will not be able to lift the package upward with 80 lbs of force
• An engine produces 90hp, and is 90% efficient. So how much horsepower is being lost because of inefficiency?

  a.)90

  b.)10

  c.)110

  d.)9

  b.)10

  
  

  *

  90/.90=100

  100-90=10
• Imagine you're using a pulley system to lift a box that weighs 100 lbs, but the pulleys are only 50% efficient.How many pounds of force are you actually putting into moving the box?

  a.)75

  b.)150

  c.)200

  d.)10

  c.)200

  
  

  *100/.50=200
• Two identical enclose containers of liquid are connected by a pipe. If one side receives 12 lbs of force, how much will the other side receive due to the connecting pipe?

  a.)1 lbs

  b.)6 lbs

  c.)12 lbs

  d.)unknown

  c.)12 lbs
• Imagine a diver practice diving at a 20ft depth in a diving pool. Where is the water pressure greatest?

  a.)Where the diver is

  b.)Halfway between the bottom and surface

  c.)It doesn't matter, water pressure is always equal

  a.)Where the diver is

  
  

  *water pressure increases by .43lbs per pound
• a.)1 in

  If the Vat A is pressurized to move the liquid level down 1 inch, how much will the water level in the other vat rise, assuming that they are the same size?

  a.)1 in

  b.)2 in

  c.)5 in

  d.)7 in

  
• An elevator motor requires 5,968 watts to move the elevator. What is the horsepower of the electric motor operating the elevator?

  a.)7

  b.)8

  c.)13

  d.)746

  b.)8

  
  

  *divide 5,968/746=8
• Jack needs to pull a truck for 1 minute. The truck weighs 115.5 tons. What's the minimum number of horsepower necessary?

  a.)3hp

  b.)7hp

  c.)21hp

  d.)420hp

  b.)7hp

  
  

  115.52,000=231,000lbs

  Divide 231,000/33,000(a single horsepower can move per minute)= 7hp
• The power need to move 550 pound one foot over the period of one second is commonly called

  a.)joule

  b.)watt

  c.)torque

  d.)horsepower

  d.)horsepower
• The smaller gear has 12 teeth and the larger gear has 24 teeth. If the small gear turns 12 times, how many revolutions will the larger gear make?

  a.)2

  b.)144

  c.)6

  d.)24

  c.)6

  
  

  *half of 12 turns is 6 turns
• Using the same image as the previous question, if gear D has twice the diameter of C, what is the mechanical advantage of D? How many revolutions will C make for every revolutions of D?

  a.)1/2

  b.)1/4

  c.)2/7

  d.)3/4

  a.)1/2

  
  

  *MA=teeth output/teeth input=24/12=2

  
• Two balls of the same density, one large and one small, roll toward each other at the same speed. When they collide, what will happen to the larger ball?

  a.)it will be propelled backward

  b.)it will jump over the smaller ball

  c.)it will continue forward

  d.)it will stop

  c.)it will continue forward

  
  

  *the lager ball will knock the smaller ball backwards
• When two or more forces act to balance each other out, the condition is called

  a.)equilibrium

  b.)static recoil

  c.)gravitational balance

  d.)concurrent forces

  a.)equilibrium
• The sideways force one feels when a car turns sharply is often called

  a.)thrust force

  b.)angle force

  c.)centrifugal force

  d.)positive force


  c.)centrifugal force
• A rope is pulling a 320-pound box up an incline that's 16 feet long. If 80 pound of force is used to move the box up the incline, how tall is the incline?

  a.)6 feet

  b.)10 feet

  c.)4 feet

  d.)8 feet

  c.)4 feet

  
  

  *MA=output force/input force= 320/80=4
• Mr.Roth's children-Jake,Paul, and Jill-weigh 80,60 and 50 pounds, respectively. They all sit on the same side of a seesaw together. Jake sits 3 feet from the fulcrum, Paul sits 5 feet from the fulcrum, and Jill sits 6 feet from the fulcrum. How far from the fulcrum must Mr. Roth sit on the other side to balance the seesaw if he weighs 200 pounds?

  a.)4.2ft

  b.)5.5ft

  c.)5ft

  d.)4ft

  a.)4.2ft

  
  

  200x=(803)+(605)+(50*6)

  200x=240+300+300

  200x=840

  x=4.2
• James applies force at one end of a hydraulic jack. The area at the other end of the jack is five times the area where James is applying the force. How much larger is the exerted force than what James is applying?

  a.)twice as large

  b.)half as large

  c.)one-fifth as large

  d.)five times as large


  d.)five times as large

  
  

  *(P1=P2)/ (P=F/A)

  
  

  P1=P2

  
  

  F1/A1=F2/A2

  
  

  F1/A1=5F1/5A1
• Four gears are connected in a series. If Gear #1 is turing clockwise, Gear #4 will turn

  a.)clockwise

  b.)counterclockwise

  c.)more quickly than Gear #1

  d.)more slowly than Gear #1

  b.)counterclockwise

  
  

  *gears connected in series turn in opposite directions of each other. Gear 1 and 3 turn clockwise(turn right); while Gears 2 and 4 turn counterclockwise(turn left or opposite)
• Not including friction, a stationary single pulley gives a mechanical advantage of

  a.)2

  b.)4

  c.)3

  d.)1

  d.)1
• Daisy' single-speed bicycle has a front gear with 48 teeth and a rear gear with 12 teeth. If Daisy pedaled at 80 revolutions per minute(rpm), how fast her wheel rotate?

  a.)280rpm

  b.)320rpm

  c.)70rpm

  d.)128rpm

  b.)320rpm

  
  

  *48/12= 4

  80*4=320
• A 600-pound weight is placed on a 10-pound board that has been evenly balanced between two scales. How much does the left measure if the weight is 2/3 closer the left than to the right?

  a.)400

  b.)300

  c.)405

  d.)410

  c.)405

  
  

  6002/3=400

  2/3= 1/2= .05

  400+5=405
• The shock absorber on a car is a very large spring. If Abra's car hits a pothole with 600 pounds of force and the shock absorber compresses 3 inches, what is its spring constant in pounds per inch?

  a.)200

  b.)600

  c.)20

  d.)1,800

  d.)1,800

  
  

  6003=1,800
• Wheel A has a diameter of 9 ft. Wheel B has a diameter of 12 ft. If both wheels revolve at the same rate, Wheel B will cover a linear distance of 24 ft.

  a.)at the same speed as Wheel A

  b.)more slowly than Wheel A

  c.)in half the time of Wheel A

  d.)more quickly than Wheel A


  d.)more quickly than Wheel A
• Two people are carrying a 100-pound crate on a 2-x-8-x-12 foot board. To distribute the load evenly between the two people, the crate should be placed.

  a.) 2 feet from the end of the board

  b.) in the middle of the board

  c.)3 feet from the end of board

  d.) the load can't be evenly distributed

  b.) in the middle of the board
• Which of the tanks will overfill if the pipe connecting to tank A is 7 gallons/minute, the pipe connecting tank A and B are 8 gallons/minute, the pipe connecting tank B and C are 9 gallons/minute and finally the pipe connecting pipe C that is 3 gallons/minute?

  a.)tank A

  b.)tanks A and B

  c.)tank C

  d.)tanks B and C

  c.) tank C
• A block and tackle is used to lift a truck engine with a weight of nearly 7,406 newtons. The input force required to lift this weight using the block and tackle is 308.6 newtons. What is the mechanical advantage of block and tackle?

  a.)23.99

  b.)15

  c.)25

  d.)24.75

  a.)23.99

  
  

  *MA=output force/input force

  =7,406/308.6= 23.99
• While throwing a football, Dan exerts a forward force of 50 newtons on the ball and pushes it forward a distance of 1.2 meters. How much work does he do on the football?

  a.)45j

  b.)60j

  c.)50j

  d.)50.5j


  b.)60j

  
  

  Work=ForceDistance

  =50*1.2

  =60 joules
• If a 200-pound barrel must be lifted 4 feet to the bed of a box truck, an inclined plane will reduce the amount of effort required to move the barrel by half if the incline plane is

  a.)2 ft long

  b.)6 ft long

  c.)8 ft long

  d.)9 ft long

  c.)8 ft long

  
  

  *x/4=200/100

  x/44=24=8
• The moisture that forms on the inside of a window on a cold day is called?

  a.)condensation

  b.)distillation

  c.)evaporation

  d.)tarnation

  a.)condensation
• A 3-inch-diameter flanged pipe with six holes is being fitted to a base with six holes. What's the maximum number of degrees the pipe must be rotated in order to line up the holes?

  a.)120 degrees

  b.)180 degrees

  c.)60 degrees

  d.)360 degrees

  c.)60 degrees

  
  

  *360/6=60
• If all the following objects are the same temperature, which one will feel coldest on a cool day?

  a.) wooden spoon

  b.) plastic spoon

  c.) metal spoon

  d.) fiberglass spoon

  c.) metal spoon
• Which of the following controls an automatic sump pump?

  a.)mechanical switch

  b.)manual switch

  c.)pneumatic switch

  d.)float

  d.)float

  
  

  *a sump pump is used to drain water