Energy

Define energy (energy is…)

Energy is the ability to do work or cause change

Define work done (work done is…)

Work done is the energy transferred when a force moves an object

Write the equation for work done (the equation is…)

Work done = force × distance moved in the direction of the force

State the unit of work done (work is measured in…)

Work is measured in joules (J)

Define power (power is…)

Power is the rate of energy transfer per second

Write the equation for power (power is given by…)

Power = energy transferred ÷ time

State the unit of power (power is measured in…)

Power is measured in watts (W)

Define kinetic energy (kinetic energy is…)

Kinetic energy is the energy an object has due to its motion

Write the equation for kinetic energy (the equation is…)

Kinetic energy = ½ m v²

Define gravitational potential energy (GPE is…)

GPE is the energy stored in an object due to its height in a gravitational field

Write the equation for GPE (the equation is…)

GPE = mass × gravitational field strength × height

Define elastic potential energy (elastic energy is…)

Elastic energy is energy stored when an object is stretched or compressed

Define conservation of energy (conservation of energy means…)

Energy cannot be created or destroyed

Define efficiency (efficiency is…)

Efficiency is the proportion of input energy transferred usefully

Write the efficiency equation (efficiency is…)

Efficiency = useful output ÷ total input

Define energy dissipation (energy dissipation is…)

Energy dissipation is the spreading out of wasted energy

Define power in terms of work done (power is…)

Power = work done ÷ time

Define thermal energy (thermal energy is…)

Thermal energy is the internal energy of an object due to particle motion

Define chemical energy (chemical energy is…)

Chemical energy is energy stored in chemical bonds

Define nuclear energy (nuclear energy is…)

Nuclear energy is energy stored in the nucleus of atoms

Define mechanical energy transfer (mechanical transfer is…)

Mechanical transfer is energy transferred by a force doing work

Define electrical energy transfer (electrical transfer is…)

Electrical transfer is energy transferred by moving charges

Define heating energy transfer (heating transfer is…)

Heating transfer is energy transferred due to temperature difference

Define radiation energy transfer (radiation transfer is…)

Radiation transfer is energy transferred by waves such as light or infrared

Define specific heat capacity (SHC is…)

SHC is the energy needed to raise 1 kg of a substance by 1°C

Define specific latent heat (latent heat is…)

Latent heat is the energy needed to change state without changing temperature

Explain why machines are never 100% efficient (they are not because…)

Some energy is always lost as heat due to friction

Define renewable energy (renewable energy is…)

Renewable energy is energy from sources that will not run out

Define non‑renewable energy (non‑renewable energy is…)

Non‑renewable energy is energy from sources that will eventually run out

Give examples of renewable energy (examples include…)

Examples include solar

Give examples of non‑renewable energy (examples include…)

Examples include coal