Chapter 13, Section 1: Work & Energy

Compound Machine

A machine that combines two or more simple machines.

Mechanical Advantage

Mechanical Advantage is defined as the ratio between the output force and the input force. It is also equal to the ratio between the input distance and the output distance if friction is ignored.

Potential Energy

Potential energy (PE) is sometimes called energy of position because it results from the relative positions of objects in a system.

Efficiency

The efficiency of a machine is a measure of how much useful work a machine can do. Efficiency is defined as the ratio of useful work output to total work input.

Kinetic Energy

The energy that ab object has because it is moving is called Kinetic Energy.

Simple Machine

The most basic machines. The six types of simple machines are the simple lever, the pulley, the wheel and axle, the simple inclined plane, the wedge, and the screw. Simple machines are divided into two families: The lever family and the inclined plane family.

Power

The quantity that measures work in relation to time is power. Power is the rate at which work is done, or how much work is done in a given amount of time.

Mechanical Energy

The sum of the kinetic energy and the potential energy in a system is called mechanical energy. Mechanical energy can also be thought of as the amount of work that something can do because of its kinetic and potential energies.

Energy

Whenever work is done, energy is transformed or is transferred from one system to another system.

Work

Work is done only when force is applied to an object and the object moves in the same direction as the applied force. Work is calculated by multiplying the force by the distance over which the force is applied.