Energy, Work, and Power Fundamentals

Practice flashcards covering the definition of energy, various energy types, environmental impacts of fuels, the law of conservation of energy, and mathematical formulas for potential energy, kinetic energy, work, and power.

Energy

The ability to get things done, to make things go, or the capacity to perform work.

Stored Energy

A classification of energy forms including chemical energy and potential energy.

The Sun

The most important source of energy for Earth; it allows plants to photosynthesise and create food.

Fossil Fuels

Traditional fuels including coal, oil, and natural gas formed from living organisms that died millions of years ago.

Acid Rain

A harmful environmental effect caused by sulphur dioxide ($SO_2$) and nitrogen oxides which corrodes buildings and kills wildlife.

Carbon Monoxide

A poisonous gas released during combustion that has a greater affinity to haemoglobin than oxygen, replacing oxygen in the blood.

Alternative Sources of Energy

Environmentally friendly energy sources including solar, wind, geothermal energy, and waves.

Law of Conservation of Energy

A fundamental law stating that energy cannot be created or destroyed, but only converted from one form to another.

Energy Converters

Also known as transducers, these are household appliances or devices that change energy from one form to another.

Wasted Energy

Energy converted into a form that is not useful to us, such as over $70\%$ of a car's chemical energy being lost as heat in the radiator and exhaust.

Potential Energy (PE)

The energy an object possesses because of its position or state, calculated using the formula $PE = mgh$.

Kinetic Energy (KE)

The energy a body possesses because of its motion, calculated using the formula $KE = \frac{1}{2}mv^2$.

Joules (J)

The unit for potential energy, kinetic energy, and work; defined as the work done when a force of $1\,N$ moves an object $1\,m$ ($1\,J = 1\,Nm$).

Fluid Friction

The resistance experienced by an object traveling through liquids or gases, such as air resistance on a car.

Newton’s Third Law of Motion

The law stating that for every action there is an equal but opposite reaction, or when Body A pushes on Body B, Body B pushes back with an equal and opposite force.

Terminal Speed

The maximum speed reached during freefall when air resistance stops acceleration, documented as approximately $2\,m/s$ for a skydiver in the text.

Work

The product of force and the distance moved in the direction of the force ($W = F \times d$).

Power

The rate of doing work or the rate at which energy is transferred, calculated as $\text{Power} = \frac{\text{Work done}}{\text{Time taken}}$.

Watt (W)

The unit of power generated when $1\,J$ of work is done in $1\,s$.

Catalytic Converters

Devices fitted to cars to remove most of the sulphur dioxide and nitrogen oxides from exhaust gases to reduce environmental harm.