Mechanical asvab

What unit is work measured in when using the formula

work is measured in joules

What formula determines how much a lever reduces the amount of effort necessary to do work?

What types of levers are pliers, scissors, and boat oars?

Class 1 levers

When two or more forces interact so their combination cancels each other out, what state are they in?

Equilibrium

What is the buildup of electrical charges on the surface of a substance?

static electricity

What units are used to measure tension force?

newtons

What determines how fast a pulley rotates?

A pulley’s diameter in relation to the pulley that’s driving it determines how fast it rotates.

What does density measure?

mass per unit volume of a substance.

What are the two main ingredients in work?

force and displacement

If 17 gears are arranged in a series, and the first gear turns clockwise, what direction will the last gear turn?

If you have an odd number of gears aligned in a series, the first and last gear spin in the same direction, so if Gear 1 turns clockwise, Gear 17 rotates clockwise.

Where is the load on a Class 2 lever?

between the effort and the fulcrum.

What is torque measured in?

Torque is measured in Newton-meters (Nm) in the SI system. or pound-feet

What is Newton’s law of universal gravitation?

every object in the universe attracts every other object in the universe

What does Einstein’s theory of special relativity tell you?

says that mass and energy are the same physical entity, and that they can be changed into each other.

What is the formula for calculating pressure?

What determines the speed at which a gear turns?

number of teeth

What does c represent in

speed of light

What is electrical force?

the production of stationary electrical charges, often the result of friction.

What unit is time measured in when using the formula

seconds

what type of pulley is depicted?

block and tackle system with a 2 to 1 advantage

Rank these materials by density, with the highest density first: packing peanuts, iron, water, and ice cubes.

iron, water, ice cubes, and packing peanuts.

What are the three main components that determine the amount of centrifugal force an object experiences?

mass, (rotation) speed, and distance from the center of the rotating object

What formula do you use to calculate the mechanical advantage of a ramp?

what type of machines are screws ?

inclined planes in spiral form

If you exert 100 pounds of force on a 100-square-inch surface, what is the amount of pressure?

you exert 1 pound per square inch (psi)

If you have an odd number of gears connected in a series, do the first and last gears turn in the same direction or in opposite directions?

the first and last gears turn in the same direction

definition of power_____

rate at which work is done

What type of lever is depicted here?

class 1 lever

What is the normal atmospheric pressure on Earth’s surface?

14.7 psi

What type of machine is a car’s steering wheel?

A car’s steering wheel is a wheel-and-axle machine

What ratio expresses the relation between these pulleys if A has a radius of 1, B has a radius of 2 and C has a radius of 4?

1:2:4

What two values do you need to know to calculate an object’s weight?

mass x gravity

Where is the fulcrum on a Class 3 lever?

beside the effort, opposite the load

what is velocity?

speed and direction which an object moves

How much more work does a machine with a mechanical advantage of 2 allow you to do with the same amount of effort?

2x the work + same effort

What type of lever is depicted here?

This is a class 3 lever

What type of lever is depicited here?

This is a class 2 lever

If you have an even number of gears connected in a series, do the first and last gears turn in the same direction or opposite directions?

the first and last gear turn in opposite directions of each other

What is Newton’s Law of Universal Gravitation?

every object in the universe attracts every other object in the universe

energy of motion____

kinetic energy

What state is an object in when two or more forces interacting on it cancel each other out?

equilibrium

Which pulley turns the slowest in this arrangement?

pulley c (it is the largest)

What can you use to decrease friction between 2 objects?

lubrication

what is stored energy called?

potential energy

What is the mechanical advantage of a machine that can move a 150-newton object with an input force of 25 newtons?

6

How is tension transmitted?

string, rope, cable, or wire when forces are acting on opposite ends

What does a vise do?

machine that holds something in a place with great force

What tool measures atmospheric pressure?

barometer

What does Newton’s Third Law of Motion say?

for every action (force) in nature, there’s an equal and opposite reaction

Power formula?

what do pulleys and gears change?

can change the magnitude (size) and direction of force

What types of levers are tweezers, staplers, and brooms?

Tweezers, staplers, and brooms are Class 3 levers

What is the formula for deriving pressure?

What types of levers are wheelbarrows, crowbars, and nutcrackers?

Wheelbarrows, crowbars and nutcrackers are Class 2 levers.

What type of gears connect shafts at different angles (not parallel)?

bevel

Force mathematical formula____

Force= Mass x Acceleration

Why are most objects non-magnetic?

In most substances, there are equal numbers of spinning electrons. Half spin in one direction and half spin in the other, which cancels out their magnetism.

When measuring power in machines using

, what unit usually represents power?

horsepower (one hp = 745.7)

what is the purpose of lubricating oil in an engine?

reduces friction between moving parts

If you’re playing tug-of-war, and your side is pulling with a force of 100 N and the other side is pulling with a force of 80 N, what is the net force?

The net force is 20 N, which is the difference between both sides.

The fewer the teeth the faster the gear rotates

true

What does a wheel-and-axle machine do to the effort you use?

a wheel-and-axle machine multiplies the effort you use and produces a greater force.

what is magnetism

attractive or repulsive force from a permanent magnet or motion of electrical charge, such as the property of attracting iron or steel with a magnet

What ratio can you use to express the relation of teeth in these two gears?

6:8 or 3:4 (reduced)

What type of fluid is inside a hydraulic jack?

A hydraulic jack uses a nearly incompressible liquid, such as oil.

what is a torque

Torque is a twisting or turning force that tends to cause rotation around an axis. Another name for a torque is a moment.

two formulas used to calculate mechanical advantage

MA=Resistance/Effort

MA=Output Force/Input Force

What are the two key factors in Newton’s Law of Universal Gravitation?

mass and distance

what units are used to measure tension force?

Tension force is measured in pounds-force or Newtons (N).

1st class lever_____

Fulcrum is in the middle

2nd class lever_______

load is in the middle

3rd class lever________

Effort is in the middle

The amount of force is never greater than the weight of the object

True (yes)