Key terms & definitions

The rate of energy transfer, measured in watts (W). One watt is one joule transferred per second.

An expression such as $a^n$, consisting of a base and an index.

The ability to direct others’ actions, make decisions or control resources.

The ability to apply strength quickly; often described as explosive strength.

The rate at which energy is transferred. Power is measured in watts (W); a megawatt (MW) is one million watts.

The ability to influence others or achieve aims despite opposition.

A relationship in which one person has more control or freedom than another, for example through money, social status or access to housing.

A compact notation for repeated multiplication; in $5^3$, the index 3 means that three factors of 5 are multiplied.

A shortened way to show repeated multiplication; for example, $2^4$ means $2\times2\times2\times2$.

A number formed by multiplying 10 by itself a whole number of times, such as $10$, $100$ or $1000$.

A number obtained by multiplying 2 by itself a whole number of times, such as $2^1 = 2$, $2^2 = 4$ or .

A number written as $10^n$, where the integer exponent $n$ shows how many factors of ten are involved.

A whole-number power of ten, such as $10^3$, $10^0$ or ${10}^{}$.

A factor written as $10$ raised to a power, used to describe the scale of a quantity.

A number written as ten raised to an exponent. Positive exponents represent repeated multiplication by ten; negative exponents represent reciprocals, such as $10^{-3}=1/1000$.

A number written as ten raised to an exponent. For example, $10^3 = 1000$ and $10^{-3} = 0.001$.

The rate at which a source supplies energy, measured in watts (W).

The power at which an appliance is designed to operate normally; it states how many joules the appliance transfers each second.

The stated power of an appliance when it operates under its intended conditions.

The maximum power a component can safely dissipate under its specified operating conditions, measured in watts (W).

A relationship in which individuals or groups exercise influence or control over one another, often with unequal power.

The rule $\frac{dy}{dx}=knx^{n-1}$ for differentiating , where is constant.

An arrangement in which representatives of different political communities share responsibility for government.

An arrangement in which political parties share responsibility for government, rather than one party governing alone.

A device that provides a potential difference to a circuit; a d.c. supply has positive and negative terminals.

Personal protective equipment worn to reduce exposure to hazards, such as eye protection or hearing protection.

A unit of concentration meaning parts per million. An atmospheric CO₂ concentration of 420 ppm means approximately 420 CO₂ molecules in every million air molecules.

Purchasing power parity: a way of adjusting monetary comparisons to account for differences in prices between countries.

A question about whether something can be carried out safely, reliably and effectively in real conditions.

A physical effect produced and filmed during shooting, rather than created digitally afterwards.