ASVAB Mechanical Knowledge

gears

systems that produce a massive amount of mechanical advantage

opposite

If a gear set is even the final gear will spin the _____________ way as the first gear.

Same

If a gear set is odd the final gear will spin the ____________ way as the first gear.

M= Teeth of output gear/ Teeth of input gear

Mechanical advantage equation for amount of teeth on a gear...

746 watts

1 electrical horsepower=......

500 ft-lbs

1 mechanical horsepower=... per second

33000 ft-lbs

1 mechanical horsepower=... per minute

horsepower

The power needed to move 550 pounds one foot over the period of one second is commonly referred to as ...

7hp

Jack needs to pull a truck for 1 minute. The truck weighs 115.5 tons. What's the minumum number of horsepower necessary? (multiply tons to pounds, then divide by hp per minute)

8hp

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

incompressable

Liquids are ___________.

conform

Liquids perfectly ___________ to their containers.

equally

Pressure applied to an enclosed liquid is __________ distributed throughout it.

Pressure= Force/Area

What is the formula for pressure?

0.43

For water, there is about ______ pounds of pressure per square inch for every foot of water depth

Divide the output by the efficiency

If given a problem with and output and efficiency of the output, what do you do to find the initial force?

fixed pulley

A _______________ is when a rope or chain or something similar is wrapped around a wheel or axle in order to raise or move a weight.

changes

A wheel/axle simply __________ the direction of the force exerted to move the weight

increase

Multiple pulleys _______ mechanical advantage.

four

The mechanical advantage of a four legged pulley is equal to _____ times the effort initially expended toward moving the object.

MA=W/T=n

The equation to find out how many times a rope should wrap between the fixed pulley and the movable pulley is...

Mechanical Advantage= Weight/Tension= number of legs

MA=W/T=n

No

A man is trying to lift a 200 lb weight with 80 lbs of force with a double pulley (2x). Will he be able to move it up?

lever

Every ________ must have a fulcrum, resistance, and applied effort.

fulcrum

A point at which the lever rotates.

resistance

The force acting against the effort applied.

applied effort

The application of effort to move the lever.

Second class

What kind of lever? (Fulcrum, Resistance, Force)

Third class

What kind of lever? (Resistance, Force, Fulcrum)

First class

What kind of lever? (Resistance, Fulcrum, Force)

joule

The unit of measurement of work is the _______.

1 joule= newtons x meters travelled

Joule equation...

19800 J

If a rock climber expended 660 newtons up a 30 meter cliff, how much work (joules) did he exert?

Work

________ is defined in terms of force expended to displace an object over distance.

MA=l/w

Mechanical advantage equation for a wedge...

7

If a wedge has a length of 21 cm and a width of 3 cm, what is the mechanical advantage?

pascal's law

The amplification of force in a hydraulic system

vector quantity

Gravity is a type of force, and since force has magnitude and direction it is known as a ...

2KE = mv2

Which of the following describes the relationship between kinetic energy, mass, and velocity?

KE = ½(mv)2

Kinetic energy is defined as... (formula)

2

At minimum, how many pulleys are there in a block and tackle system?

decreases

As torque increases, speed ___________.

increases

As torque decreases, speed __________.

equal

When the distance of a life is the same as the distance the initial force travels, the force in will ______ the force out.

decreasing; horizontally

Making a wedge longer relative to its height (less slope) will change this by ____________ the amount of lift that takes place as the wedge is moved ______________.

Gravity's relationship to mass

What is a component of potential energy?

Kinetic energy

Energy in a moving object.

Potential energy

Energy that can be released under certain conditions.

Chemical energy

Energy stored in chemicals, such as in a flashlight battery.

Electric energy

Energy in moving electrons in an electric current.

Nuclear energy

Energy released by reactions in the nucleus of an atom.

Solar energy

Energy in the heat and light from the sun.