Energy and Matter Review

These flashcards cover key vocabulary from the physics lecture on energy stores, renewable and non-renewable energy resources, work, power, and the properties of matter including density and latent heat.

Geothermal energy

The use of water or steam naturally heated by processes within the Earth's crust and below for the generation of electricity.

Pumped storage

A scheme where excess energy from other sources is used to pump water into an upper reservoir when demand is low, for later release through turbines when demand is higher.

Specific heat capacity

The amount of energy it takes to increase the temperature of $1\,kg$ of a material by $1\,^{\circ}C$. Documented by the equation $\Delta E = mc\Delta \theta$.

Principle of conservation of energy

A rule stating that energy cannot be created or destroyed, and the total amount of energy in a closed system is constant.

Kinetic energy

The energy possessed by a moving object, calculated using the formula $E_k = \frac{1}{2}mv^2$.

Elastic potential energy

The energy stored in an elastic object when its shape is changed, such as a stretched spring, calculated as $E_e = \frac{1}{2}ke^2$.

Power

The rate at which energy is transferred or the rate at which work is done, given by the equation $P = \frac{E}{t}$ or $P = \frac{W}{t}$.

Fossil fuels

Non-renewable energy resources like coal, oil, and gas that release greenhouse gases and sulfur dioxide (causing acid rain) when burnt.

Nuclear power sources

Energy sources like uranium and plutonium used in nuclear power stations that do not contribute to global warming but produce radioactive waste.

Biomass

Biological material used as fuel that is considered carbon neutral because it absorbs $CO_2$ while growing.

Work done

The energy transferred to an object when a force makes it move, calculated as $W = Fs$.

Chemical energy store

The energy stored in the bonds between atoms, including fuels, foods, and chemicals in batteries.

Internal energy

The energy in an object due to the random motion and position of its particles.

Gravitational potential energy

The energy an object has due to its position in a gravitational field, calculated as $E_p = mgh$.

Specific latent heat

The energy needed for $1\,kg$ of a substance to change its state without changing its temperature, calculated with $E = mL$.

Density

The mass per unit volume of a substance, defined by the equation $\rho = \frac{m}{V}$.

Physical changes

Changes of state (solid, liquid, and gas) where no new substances are produced and the mass remains unchanged.

Brownian motion

The random, unpredictable motion of smoke particles in air, which provides evidence for the random motion of gas molecules.

Specific latent heat of fusion

The energy needed to change $1\,kg$ of a substance from solid to liquid with no change in temperature.

Specific latent heat of vaporisation

The energy needed to change $1\,kg$ of a substance from liquid to vapour with no change in temperature.