Physics

Question 1

magnetic

Answer 1

magnetic domains inside a
magnetic material that create a field;

Question 2

thermal

Answer 2

a hot object stores more thermal
energy;

Question 3

kinetic

Answer 3

(movement) – a substance may be made of vibrating particles;

Question 4

chemical

Answer 4

energy is stored in the bonds
between atoms in a molecule;

Question 5

ELECTROSTATIC

Answer 5

charged particles in an electric
field;

Question 6

ELASTIC POTENTIAL (EPE)

Answer 6

in stretched springs, rubber bands, etc;

Question 7

GRAVITATIONAL POTENTIAL (GPE)

Answer 7

the higher an object is, the more GPE it has;

Question 8

NUCLEAR

Answer 8

stored within the nucleus of an atom.

Question 9

MECHANICAL

Answer 9

this includes kinetic energy,
GPE and EPE;

Question 10

ELECTRICAL

Answer 10

tiny charged particles
flowing around a circuit;

Question 11

HEATING

Answer 11

transfer of thermal energy
from one place to another;

Question 12

RADIATION

Answer 12

energy may be transferred in
waves of light or sound.

Question 13

machines

Answer 13

A machine is a device that can convert one type of energy to another.
This can be represented by a simple energy flow diagram.
We can measure how much energy is transferred using a unit called the
joule (J).

Question 14

conservation of energy

Answer 14

The CONSERVATION OF ENERGY states that:
energy cannot be created or destroyed; it can only
be converted from one form to another (or stored).

Question 15

energy density

Answer 15

The energy density of a fuel is a measure of how much energy the fuel provides per unit
of its mass (how many joules provided per gram of fuel).

Question 16

national grid

Answer 16

Electricity is generated in power stations (of different types), then it is transmitted around the country using a network of transformers and cables called the National Grid.

Question 17

thermal power stations

Answer 17

A thermal power station heats water to create steam. This is often done by burning a fuel (storing chemical energy) or using nuclear energy.

Question 18

burning fossil fuel

Answer 18

For many years, power stations have burned fossil
fuels (coal, oil and methane gas), but this leads to
problems. Firstly, the fossil fuels are non-renewable resources
– they take millions of years to form, but they are being used up at a much faster rate, so we will eventually run out.

Question 19

the greenhouse effect

Answer 19

If the same amount of energy enters and leaves the Earth’s atmosphere, the Earth’s temperature remains
constant.
If more energy escapes, the planet cools down…

Question 20

global warning

Answer 20

The problem is that the carbon dioxide we release stops some of the energy being released back into space – the Earth retains the energy, so the planet gets warmer – this is known as global warming.

Question 21

whats is ‘work’

Answer 21

WORK is the process of TRANSFERRING
ENERGY. We say that an object has energy, but
the object does work when it transfers that
energy to another form.

work done = force x distance

Question 22

what is ‘power’

Answer 22

POWER is the RATE at which WORK is done.
A more powerful object can do the same amount of work in less time, or more work at the same time, as a less powerful object.

power= work done / time taken

Question 23

energy efficiency

Answer 23

For a machine to be considered as efficient, it must convert most of the input energy into useful forms, and waste little energy.

Question 24

what is ‘efficiency’

Answer 24

EFFICIENCY is a measure of how much energy put into a device is
transferred to a useful form.

efficiency= useful energy output / total energy input

Question 25

sankey diagram

Answer 25

A Sankey diagram is a more sophisticated version of the energy flow diagram. its arrows are drawn to scale, so the efficiencies of two devices can be easily compared.

Question 26

electrical power

Answer 26

A more powerful device transfers energy at a faster
rate (POWER = ENERGY ÷ TIME), but we can
calculate the power in an electrical appliance using
a different equation:
power = current x voltage