Chapter 6: 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.

Gear

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

Energy

________ is always transferred from the object that is doing the work to the object on which the work is done.

Screw

Like the ________, the wedge is also a simple machine in which the inclined plane moves through an object or material.

Wedge

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

Wheelbarrow

A(n) ________ is a second- class lever.

Car Jack

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

Mechanical Advantage

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

Output Work

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

System of Pulleys

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

Power

________ is the rate at which work is done.

Input Work

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

Lever

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

Work

the energy transferred 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

force that is applied to the machine

Output Force

The force applied by the machine

Mechanical Advantage

The ratio of the output force to the input force

Screw

an inclined plane wrapped in a spiral around a cylindrical post

Wedge

an inclined plane with one or two sloping sides

Compound Machine

Two or more simple machines that operate together