Chapter 7: Energy

This set of flashcards covers key vocabulary and concepts from Chapter 7 on Energy in physics.

Energy

Quantifies a system’s ability to do work; occurs in various forms and is a conserved quantity.

Work

Involves force and distance; is defined as force times distance (W = Fd).

Power

Measure of how fast work is done; unit of power is watt (1 W = 1 J/s).

Mechanical Energy

Energy due to position or motion; includes potential energy and kinetic energy.

Potential Energy

Stored energy held in readiness, capable of doing work; example includes a stretched bow.

Kinetic Energy

Energy of motion, given by the formula KE = rac{1}{2} mv^2, where m is mass and v is speed.

Work-Energy Theorem

Any change in kinetic energy is the result of work done on an object.

Conservation of Energy

Energy cannot be created or destroyed; it can only be transformed from one form to another.

Efficiency

Percentage of work put into a machine that is converted into useful work output.

Recycled Energy

Re-employment of energy that would otherwise be wasted, such as heat from power plants.

Sources of Energy

Includes solar energy, fuel cells, nuclear power, and geothermal energy as primary sources.

Mechanical Advantage

The factor by which a machine multiplies the force put into it.

Fulcrum

The point of support on which a lever rotates.

Photovoltaic Cells

Devices that convert sunlight into electricity.

Geothermal Energy

Energy derived from the heat stored within the Earth.