Chapter 5: Work and Machines

Efficiency

________: a measure of how much of the work put into a machine is changed into useful output work by the machine.

IMA

The ________ can be calculated by dividing the input distance by the output distance.

Mechanical Advantage

________: The ratio of the output force to the input force.

Power

________ is the rate at which work is done.

car jack

A(n) ________ is an example of a machine that increases an applied force.

Wedge

The ________: an inclined plane with one or two sloping sides.

second class lever

For a(n) ________, the output force is located between the input force and the fulcrum.

system of pulleys

A(n) ________ can change the direction of the input force and make it larger.

class lever

For a first- ________, the fulcrum is located between the input and output forces.

third class lever

For a(n) ________, the input force is applied between the output force and the fulcrum.

gear

A(n) ________ is a wheel and axle with the wheel having teeth around its rim.

Lever

________: a bar that is free to pivot or turn around a fixed point.

input work

The ________ is the product of the input force and the distance over which the input force is exerted.

output work

The ________ is the product of the output force and the distance over which that force is exerted.

Oil

________ reduces the friction between two surfaces.

Work

the transfer of energy that occurs when a force makes an object move

Power

the amount of work done in one second

Machine

a device that makes doing work easier

Input Force

The force that is applied

Output Force

The force applied by the machine

Mechanical Advantage

The ratio of the output force to the input force

Efficiency

a measure of how much of the work put into a machine is changed into useful output work by the machine

Simple Machine

a machine that does work with only one movement of the machine

Lever

a bar that is free to pivot or turn around a fixed point

Wheel and Axle

a simple machine consisting of a shaft or axle attached to the center of a larger wheel, so that the wheel and axle rotate together

Inclined Plane

A sloping surface, such as a ramp that reduces the amount of force required to do work,

The Screw

an inclined plane wrapped in a spiral around a cylindrical post

The Wedge

an inclined plane with one or two sloping sides

Compound Machine

Two or more simple machines that operate together