Flashcards › Mechanical › ASTB Mechanical Comprehension Test

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Side ASide B

The wheels are connected by a belt. As the wheel on the left makes one revolution, the wheel...

more than one revolution

If the wheel on the left turns clockwise, in which direction does the wheel on the right turn?ClockwiseCounterclockwise

Counterclockwise

A woman sits in a dragster at the beginning of a race. As the light turns green, she steps...

More than while stationary

All the gears in the system are moving and Gear 1 rotates clockwise. What other gears in the...

3 and 5

In which case is less force needed to move weight (W) up the ramp?ABThe force is the same in...

A

If each pendulum is released from the position shown, which pendulum requires the longest amount...

B

The voltage drop or potential difference is greater across which resistor?RaRbIt is the same...

It is the same across either resistor

If the large portion has 3 times the surface area of the small piston, how far must the small...

3 inches

If you had to swim across a fast moving stream exactly perpendicular to the banks, when you...

Directly across from where you startedAccording to the answer sheet given, directly across...

If the three squad leaders are to stay on line, which of them must turn the most slowly?ABC

C

In order to balance the scale above, the fulcrum should be movedtoward Atoward Bin either directions

toward B

If the scale was balanced before u moved the fulcrum, which of the balls is more dense?Ball...

Ball B

Where would it be best to hold a pruners' handles while trying to cut a branch?ABIt does not...

B

If the current leaves the battery in the direction shown in the diagram, what is the direction...

A

The voltage drop is greater across which resistorRxRyIt is the same across either resistor

Rx

Where is the current greater in the circuit?Greater at A than BGreater at B than AThe same...

The same at A and B

X, which has a negative charge, is positioned between a positive charge (A) and a negative...

A

In a stream, water flows through narrow and wide sections. In which sections does the water...

Narrow section

At what point is the velocity of a bullet fastest?When it leaves the muzzleWhen it reaches...

When it leaves the muzzle

The rate of heat exchange is faster betweenan ice cube and 100° glass of wateran ice cube...

an ice cube and 100° glass of water

If two glasses of water 40° and glass A was 1/2 full whle glass B was 3/4 full, which glass...

B

Did you read a mechanical comprehension hand out?No, but I will now.No! What hand out?Yes,...

Yes, and I understood everything.

If the large pistion has 2 times the surface area of the small piston, how far must the large...

1/2 inch

When the wheels X are turned at the same speed, which turns wheels Y faster?Wheel X1Wheel X2They...

Wheel X1

Imagine if wheels X where the front sprocket of a bicycle and wheels Y the rear sprocket....

System A

If wheel X1 is exactly twice the size wheel Y1, and wheel X1 is turned one time, how many times...

Two turns

In system A, as wheel X1 makes one revolution, point Atravels a greater distance than point...

travels the same distance as point B

Above is a cross section of a wing. Air travels over it and under it. As the wing moves through...

greater above the wing

When the plug in the tube is removed, water flowsinto the tubeout of the tubeneither way

into the tube

For which position of the weight is the tension on the string at point X greater?ABIt is the...

B

When is it more difficult to hold an inflated beach ball under water?Close to the surfaceDown...

Down deep

When does a beach ball seem more buoyant?Close to the surfaceDown deepThe buoyancy is the same...

Down deep

Which weight exerts less pull on the horizontal bar from which the weights hang by strings?ABEach...

A

A submarine is traveling through the ocean when its outer hull cracks and air pushes out of...

A

A submarine is traveling through the ocean when its outer hulls cracks and air pushes out its...

towards the starboard

If the board to the left was placed in water, in what orientation would it float?A higher than...

B higher than A

If two resistors and a battery are arranged in each of the above circuits, which circuit arrangement...

Circuit A

The lever above is anchored just to the left of point A. If one were to raise it one inch measured...

more than one inch

In which case is more force needed to raise the weight?ABThe force is the same in each case

A

Which system requires more rope to be pulled to lift the weight the same distance?ABThey require...

B

Which pendulum takes less time to make one swing?ABEach takes the same time to make one swing

A

If pendulum A was the same length as pendulum B, which pendulum would take more time to make...

Each would take the same time to make one swing

Newton's First LawAn object in motion will stay in motion, object at rest will stayin motionat...

at rest

Newton's Second LawForce = Mass * GravityAccelerationVelocitySpeed

Acceleration

Newton's Third LawFor every action there isa) an equal and opposite reactionb) a varied responsec)...

a) an equal and opposite reaction

Speed of conduction, which occurs in solids and stationary liquidsa) creates more heat across...

c) depends on the temperature difference

Butcher Knives, Axes, Nail Cutters, are examples ofLeversPulleysWedgesScrews

Wedges

This device is typically used to measure wires, spheres, shafts and blocks.MicrometerMultimeterTape...

Micrometer

Compressing air in a closed place will _______ the volume and ______ the pressuredecrease,...

decrease, increase

Bernoulli's principalapplies to liquidsapplies to airinvolves flow and pressureall of the above

all of the above

This class of lever is like your everyday
crowbar. The fulcrum is in the middle with the...

First class lever

On this class lever, the fulcrum is on
the end, the resistance force, the load, is in the...

Second class lever

On this class lever, the fulcrum is on the end of one side,
the effort force is in the middle,...

Third class lever

The formula for force is

mass times acceleration

The maximum weight, W, that can be lifted as shown with a pull of 100 lbs is100 lbs200 lbs300...

200 lbs

A 5 kg wad of clay is tied to the end of a string. A 300 gm copper moving horizontally is embedded...

8.3 m/s

Which exerts a larger force over a distance?A small force over a long distanceA large force...

A small force over a long distance

The formula for Work is

Force x distance

The formula for Efficiency is

Workout/Workin , since friction causes inefficiency. The fraction is never greater than...

A force acting on a surface is called pressure, and is calculated by

Pressure = Force / AreaCan be used for fluid pressure and atmospheric pressure

An observer standing on the ground sees you running 55 mph. If you were running towards the...

45 mph

A 300 lb weight rests on a hydraulic surface with an area of 376 square inches (2 square ft)....

28.8 lbs

Pressure in liquids that are not moving is called ________ pressure, and is caused by ______....

hydrostatic/gravity/increases

____________ pressure is caused by the weight of the air between the earth's surface and space.HydraulicAtmosphericHydrostatic

Atmospheric

Energy travels from objects of different temperature in the form of _____ through the process...

Heat

_________ occurs in liquid and gases by calculating currents caused by a difference in density....

Conduction/Convection/Temperature

Electrical forces are caused by electrical charges which may be positive or negative.Which...

Electrical forces decrease as the distance between charge particles increases.

This circuit element dissipates energy through heatResistorsCapacitorsInductorsDiodesTransformers

Resistors

This circuit element stores electrical energy between two parallel platesResistorsCapacitorsInductorsDiodesTransformers

Capacitors

This circuit element stores magnetic energyResistorsCapacitorsInductorsDiodesTransformers

Inductors

This circuit element restricts current to only one direction. A semiconductor used as a rectifier....

Diodes

This circuit element is used to convert electricity from one voltage to anotherResistorsCapacitorsInductorsDiodesTransformers

Transformers

The two kinds of circuits that you are responsible for are:

Parallel circuitsSeries circuits

These kinds of circuits are identifies by seeing sever circuit elements, (resistors, lights,...

Parallel circuits, and in this circuit, the current gets divided between two or more elements

In these kinds of circuits, all of the circuit-elements are in a row along a single wire similar...

Series circuits, and in this circuit, the voltage will continue to drop as it passes through...

What is Ohm's law?

I = V/R

As you follow the path of the current from the positive node away from the battery and through...

Voltage drop

The theory behind leverage is that the longer the lever, the more ______ u produce.forcetorquedistanceweight

torque, which is the product of force and distance

Doubling the length of the lever-arm would ________ the torque that you apply.

double

The torque created by the hand must _______ the torque produced by the weight before it can...

Equal

Left Side:Force = 60 lbsDistance to fulcrm = 8 ftRight Side:Force = ?Distance = 15 ftForce...

32 lbs

The _______________ of a lever is calculated by dividing the arm-length that you are applying...

Mechanical Advantage

What is the formula for the Mechanical Advantage of a lever?

Effort Arm / Resisting ArmMA = length of effort arm ÷ length of resistance arm.

What is the Mechanical Advantage of in the diagram?11.441.882

1.88

You may see problems where weights and forces are acting on a single lever arm. It's possible...

clockwise and counterclockwise

Solve for the unknown force or distance11 lbs15 lbs10.9 lbs33 lbs

11 lbs

A pendulums has three weights attached, each 8 in away from each other. One string is...

a) The one with the longer string takes the longest to make one complete swingThe weight does...

You had two tennis balls and held them over a 10 story building, and you dropped Tennis ball...

They hit the ground at the same time

Pushing a weight up an incline requires only a fraction of the force needed to lift the weight...

all of the above

For a height of 5, and a slope-length of 10, the Mechanical Advantage in the diagram is101512

2

The mechanical advantage for a pulley systema) equals the number of ropes within the systemb)...

equals the number of ropes within the systemOnly MOVEABLE pulleys provide mechanical advantage

The load is supported by how many strands of rope?1234

3

If the pull of the truck in the diagram is 100 lbs, what is the maximum weight of the object?100...

400 lbsNOTE: Also the weight will raise 1 ft for every 4 ft you pull

When several ropes are in contact with the weight, they all contribute equally. Tension is...

the force that the rope sustains internallythe force that is needed to move the weight is

__equal__...In the figure, there are ropes holding the weight up. Therefore they each contribute ____ of...

1/3

This specifies the change in position of a point in reference to a previous position. In simple...

Displacement

R = (D*R)/d is the formula forRadiusRangeGear Revolutions

Gear Revolutionsr=(D*R)/d ; r*d=R*D

Hydrometers use floats to measurespecfic gravitydisplacementhardness of wateramounts of water

specfic gravity

Specific gravity is the weight of a ______ compared with the weight of the water.solidgasliquidmass

Liquid

The liquid with the highest specific gravity will causethe float to rise higher in the glass...

the float to rise higher in the glass tube

Pliers and scissors are ________ levers and explain where the fulcrum of the lever is.First...

First class.The fulcrm is in the middle

A nutcracker or wheelbarrow are _________ levers.First ClassSecond ClassThird Class

Second class.The fulcrum is at one end, load is in between.

Tongs or tweezers are examples of _________ leversFirst ClassSecond ClassThird Class

Third ClassFulcrum is at one end, effort is in between.

In pulley's, the smaller pulley will turn _______ than those larger than it.FasterSlowerSame...

FasterIt has to "keep up" and therefore turns faster.

a* d = A * Da = aread = displacementA = bigger aread = bigger displacementThis is the formula...

Mechanical Advantage in a piston

An axe is classified as a wedge, which is aninclined planefirst class leversecond class leverthird...

inclined plane

The __________ the fulcrum is from the resistance arm, the __________ amount of force that...

closer, greater, higher

No electricity flows through burnt out bulbs, but a ________ can bypass it if connected on...

voltimeter

Which of the following is true:Current and Voltage varies in a parallelCurrent is constant...

Current is constant in a series, voltage is notCurrent * resistance = voltage

The current with the _______ resistance is usually in series, because it forces the current...

greater

In a 2 pulley system, the movable pulley will only move up half the distance, and spin half...

No answer. That was a statement.

What is the rpm for this wheel, that requires 2 contacts per second?1516488

15twice per second = 120 contacts per minute. 8 rods on wheel. 120/8=15

Heat is a form ofcaloriesmotionenergypressurization

energy

On a standard day, at sea level, assuming static conditions, the speed of sound is1100 ft per...

1100 ft per sec

For a plane to fly, air flowing over the top of a wing creates a vaccum, while the air flowing...

a) remains at approximately the same air pressure

The diagram depicts airflow around the wing of an aircraft. Most of the lift is caused bya)...

d) decreased air pressure on the top side (side A)

In the diagram, which of the ff statements is not true?a) pulley 2 would spin faster than pulley...

c) pulley 1 would spin faster than pulley 3according to the book

Which tool below is the best for cutting metal?hacksawchainsawrotary sawhandsaw

hacksawhacksaw was designed for metal.

Which of the ff is a type of lever?elevatorseesawdoor hingeelectrical cord

seesaw

What is the formula of force for a lever?

Fᴱ = FL dL / dᴱFormula can be changed toFᴱ dᴱ = FL dLFᴱ = effort force (N, lb)FL...

Approx how much force must be exerted to lift the box?67 lbs100 lbs250 lbs258 lbs

67 lbsFᴱ dᴱ = FL dLFᴱ 30ft = 200lb * 10ftFᴱ 30ft = 2000lbftFᴱ = 2000lbft/30ftFᴱ...

Which wrench would require more force to turn a bolt?Wrench AWrench BNo DifferenceNone of the...

Wrench A

In order to move the block five feet, how many feet of rope would have to be pulled?5101520

15

The number of cranks the crankshaft of a V-6 engine has is2468

66 pistons, 1 crank per piston

Pulley A is the same size of Pulleys B and C, and twice the size of Pulley D. For each revolution...

twoaccording to the book, two.

In order to lift a 100 lb load onto a dock five feet high, using only 25 lbs of force, how...

20 ft100 / 25 = 44 = required MA for an inclined plane4 * 5 feet high = 20 ft

One horsepower is equal toa) 33,000 ft-pound work per minb) 150 lbs of force in an hourc) 950...

a) 33,000 ft-pound work per min

In the diagram, how many pulleys are turning in a clockwise direction?onetwothreefour

fouraccording to the book, 4

Wheel A has a diameter of 10 inches. Wheel B has a diameter of 25 inches. If both revolve at...

Wheel B

How many gears are turning in a counterclockwise direction?twothreefourfive

three

If Gear 1 has revolves twice, how times will Gear 2 revolve?1234

1The picture would have 2 gears, a small 10 tooth, and a large 20 tooth.

In the figure, for each complete revolution of the cam, how many times will the valve open?1234

3

What is the area of a cylinder?

2(π r²) + (2 π r)* h

In the hydraulic system depicted, the cylinder on the left has a diameter of 2 inches and the...

900 lbs

In the design, which tank(s) will overfill?Tank ATank BTank A and CTank B and C

Tank A and C

Which of the following are not parts of a braking system of an automobile?discsmaster cylinderaxelwheels

axel

On a braking system, the axel supports the wheel, but is not part of the braking system. The...

master cylinder

When a machine magnifies force, it is referred to asmagnification factormechanical advantageleverage...

mechanical advantage

A

__pitch__isa) the distance between the threads of a screwb) the gap measurement of a...
a) the distance between the threads of a screw

When an object is at equilibriuma) its velocity does not changeb) the object speeds upc) the...

a) its velocity does not change

Equilibrium isa) when at object is at restb) when 2 or more forces act to cancel the effects...

b) when 2 or more forces act to cancel the effects of each otherAn object at equilibrium may...

An example of a simple machine isa door hingelight switchcan openerall of the above

all of the above

When a helium-filled ballon rises, the force responsible isfrictionair pressurebuoyancygravity

air pressure

In physics, power can be defined aswork/timeenergy/efficiencyleverage/massfriction/drag

work/time

The force acting on an object dropped from a building isbuoyancyelastic recoilgravityequilibrium

gravity

If you remove your foot from the gas pedal in ur car, it will slowly coast to a stop. The force...

friction

If a driver wheel is present, the adjacent wheels will rotate according to how _________ to...

closeThe closer to the center, the faster it will move.

By increasing the length of the lever arm, the effort is increased, enabling a valve to blow...

b) moving the lever farther will cause less effortNOTE: ...and lets the valve blow up at a...

What is the formula to find the volume of a sphere?

4/3π r³

What is the formula to find the area of a sphere?

4 π r²

If two weights hang from two different strings attached to a bar, less pull is exerted by the...

b) the length of the string does not matter

The deeper you go with an inflated ball, the more difficult it is to hold it underwater. So...

b) will increase, depending on how deep you go into the water

Rate of heat exchange is _____ through objects of greater temperature differenceslowerthe same...

faster

Think about putting your thumb on the end of a hose makes the water spray.a) water flows faster...

c) all of the above

This kind of engine consists of an intake, compression, combustion, and exhaust.2 stroke4 stroke8...

4 stroke

What is the mechanical advantage of a wheel and axle?

radius of axel to handle divided by the radius of the drumradius(axel to handle)/radius(drum)

Statics and EquilibriumFormula for a moment?

Force * distance

________ energy is stored in an object while _________ energy is energy in motion.Kinetic,...

Potential, Kinetic

I = Q/TDefine I, Q, TCurrent, charge, timeVoltage, momentum, timeVoltage, charge, timeCurrent,...

Current, charge, time

This device measures the current flow in a circuitAmmeterVoltmeterMultimeter

Ammeter

This device measures does the job of both measuring the flow in a current and the voltageAmmeterVoltmeterMultimeter

Multimeter

The formula for Power is

Power = volts * amperes

Units for a charge iscoulomb, Campere, Avolts, Vwatts, W

coulomb, C

Units for current flow arecoulomb, Campere, Avolts, Vwatts, W

ampere, A

ViseMA = (2*pi*length of handle) divided by what?

pitch of thread

Formula of Weight isMass * GravityGravity is equal to9.81 m/s²32.3 ft/s²22.1 mph

9.81 m/s²All the other answers are off by 0.1 only.32.2 ft/s²22 mph

The formula for Density is

Mass / Volume

The formula for Relative Density is

Density / Density(Reference Material)

If you add salt into a liquid, the solution has a lower freezing point. This is becausea) there...

a) there is an increase in specific gravitySpecific gravity usually means relative density...

Heat alwaysdistributes between objectstravels from hot to cold

travels from hot to cold

Compressing air in a closed place will decrease the volume and raise the temperaturea) Trueb)...

True

A square plate is hanging by 4 wires (one on each corner). One breaks, and it's hanging by...

b) the 2 diagonally across from each other hold an equal amount that is more than the lone...

Will an airplane with engine and propeller take off on a treadmill or converyor belt, regardless...

Will a glider (no engine or propeller) take off on a treadmill or converyor belt, regardless...

A common example of a first-class lever isa seesawa wheelbarrowtongs

a seesaw

The force F required to balance the weight of 60 lbs on the lever, shown in the diagram above,...

210 lbs

The mechanical advantage shown is458

5

What effort must be exerted to the handles of the wheelbarrow shown carrying a load of 200...

50 lbs

The bar, which is exactly 4 inches in length, has a 275 lbs weight on one end and a 125 lb...

1 1/4 inches

Neglecting friction, what is the mechanical advantage in using a single fixed pulley as shown...

1

In the figure shown, the pulley system consists of a fixed block and a moveable block. Neglecting...

50 lbs

The weight W is to be raised as shown in the figure by attaching the pull rope to the truck....

24 ft

The formula for an inclinded plane isMA = L/HMA = mechanical advantageL = lengthH = ?

H = heightMA = L / HL = length

A gradual slope will provide a ________ mechanical advantage than a steep slope.higherlower

higher

In the figure shown, the service person is using a plank to roll a 300-pound barrel up to the...

100 pounds

How do you find the mechanical advantage for a wheel and axel?

Diameter/Radius

In the figure shown, a bucket is being raised by a wheel-and-axel arrangement. If the distance...

4

To make a 1/2" hole in a block of wood, use toolABC

B

To cut a thread on a 1/2" brass rod, use toolABC

A

The number 18 appearing on the tool shown above indicatesdepth of openingsize of openingthreads...

threads per inch

Which of the 1½ volt dry cell battery connections shown above will deliver 6 volts?123

2

In the figure given, if the thickness of the wall of the pipe is ½", the inside diameter of...

3"

The figure above represents a revolving wheel. The numbers 1 and 2 indicate two fixed points...

c) points 1 and 2 make the same number of revolutions per minute

In the figure shown, if gear A makes 14 revolutions, gear B will make141721

21

With the wheels in the position shown in the figurea) wheels S and T will rotate in opposite...

b) wheels S and T will rotate in the same directions

In order to open the valve four times every second, the wheel must rotate at12 rpm18 rpm24...

24 rpm4 times every second = 24010 rods on the wheel240/10

In the figure shown, a 160-lb individual jumps off an 800-lb raft to a point in the water 10...

a) 2 ft in the opposite direction

The figure shows a lever-type safety valve. It will blow off at a lower pressure if weight...

moved to the left

As shown in the figure, four air reservoirs have been filled with air by the air compressor....

100 lbs

In the figure above, the number of complete turns the vise handle must make to fully close...

18

In the figure shown, the center-to-center distance between the two poles is1 3/4"1 15/16"1...

1 15/16"

If an 8" level indicates 16 quarts of oil in the tank, then the number of quarts of oil to...

4 quarts

Which illustration depicts the compression stroke?XYZ

ZBoth valves are closed and the piston is moving upwards

What is the proper sequence of the four strokes of a piston in a gasoline engineW X Y ZX Z...

Y Z X W

The gauge shown above is adepth gaugefeeler gaugethread gauge

thread gaugeThe thread or screw-pitch gauge is used to determine the pitch and number of threads...

The wrench shown is generally used whena) a definite force must be applied to a nut or bolt...

a definite force must be applied to a nut or bolt headThe torque is read visually on a dial...

Which of the figures shown is the proper procedure for pulling adjustable wrenches?ABBoth are...

AThe handle of the adjustable wrench should be pulled toward the side having the adjustable...

Every object in a state of uniform motion tends to remain in that state of motion unless an...

True

Newton's Law describes a relationship between an object's _______ and _______ as the...

mass, acceleration

In Newton's Third Law, forcea) is neither created or destroyedb) if there is no opposing force,...

c) always elicits an equal, opposite force acting against itWhenever a first body exerts a...

A 150 lb man jumps off a 600 lb raft to a point in the water 12 ft away. Theoretially, the...

3 ft in the opposite direction150 lb x 12 ft = 600 lb x ? ft

The mechanical advantage of a lever can be increased bya) placing the fulcrum closer to the...

d) both a and c

A lever arm is in balance when the force x length of one side of a fulcrum is equal to the...

10 lbs

Then tension of a string in figure A is greater than the tension of a single spring in Figure...

L) Three times greater than in B

Pulleys. Which of the following is always not true about a pulley.a) a pulley system will...

e) all of the above

What amount of force is required to move the weight (assume the supported objects all weight...

50lbs

What amount of force is required to move the weight (assume the supported objects all weight...

33.3 lbs

What amount of force is required to move the weight (assume the supported objects all weight...

25 lbs

The immoveable one pulley system provides ___ the force to lift the object and will have a...

1/2There is 1 rope. Divided evenly into 2, and no mechanical advantage, since the pulley is...

If the pulley is immoveable, what is the minimum force that must be applied to position 1 in...

10.1 lbs over 3 ft

This is Boyles Law:a) Compressing a gas to 1/2 volume doubles the pressureb) If the pressure...

c) Both A and BActually, Boyle's law describes the inversely proportional relationship between...

Charles' Law is whena) you heat some liquid, and the temperature changes, but the volume stays...

b) you open a can of coke, and the soda starts fizzing outIf gas is held at a constant pressure,...

Bernoulli's Principal is whena) a good pitcher throws a curve ballb) you siphon a gas tankc)...

d) both a and bBernoulli's princiapl states that as the velocity of a fluid increases, its...

The higher the altitude, the more dense the air.TrueFalse

False

The deeper an object is submerged, the more pressure is exerted upon it.TrueFalse

True

Which of the statements about weight are true?a) Weight is the same closer to the earth's surface...

b) Weight is greater on planets with greater massMass does not change and is not affected by...

If Gear R is thedriver, at the moment shown, Gear S isP) not movingQ) jammedR) moving at its...

T) moving in the opposite direction as Gear R

If Gear A makes 14 revolutions, gear B will makeA) 9 revolutionsB) 14 revolutionsC) 17 revolutionsD)...

D) 21 revolutions

_______ is the factor or ratio by which a mechanism multiplies the force or torque applied...

Mechanical Advantage

__Output force__Input force__ordistance w/c force is applied...__