P1

Question 1

types of energy

Answer 1

kinetic
thermal
electric
gravitational
chemical
elastic
magnetic
nuclear

Question 2

what happens when an object falls?

Answer 2

It gains speed and its store of gravitational potential energy decreases and its kinetic energy store increases

Question 3

Friction

Answer 3

work done to overcome friction is transferred as energy to the thermal energy stores of the objects that rub together and the surroundings

Question 4

gravitational potential energy

Answer 4

gpe store of objects increase when moving upwards and decrease when moving downwards, because work is done on it to overcome gravitational force

Question 5

energy dissipation

Answer 5

• wasted energy is transferred to the surroundings which become warmer
• as energy dissipates it gets less and less useful

Question 6

How can machines be made more efficient?

Answer 6

Machines can be made more efficient by reducing the energy they waste by lubricating them to reduce friction between parts.

Question 7

conductivity

Answer 7

• metals are the best conductors of energy
• non metals are the best insulators
• the higher the thermal conductivity the higher the rate of energy transfer
• the thicker the insulating material the lower rate of energy transfer through it

Question 8

heat capacity

Answer 8

measures how much heat is needed to raise an objects temperature by 1 degree celsius

Question 9

specific heat capacity

Answer 9

the amount of heat energy needed to raise the temperature of 1kg by 1 degree celsius

Question 10

infrared radiation

Answer 10

• the higher the temperature of an object, the more infrared radiation it emits
• an object that has a constant temperature emits radiation across a continuous range of wavelengths

Question 11

blackbody radiation

Answer 11

radiation emitted by a body that absorbs all the radiation incident on it

Question 12

biofuels

Answer 12

biofuels are renewable sources of energy such as methane and ethanal which can be used to generate electricity.

Question 13

non renewable energy sources

Answer 13

• coal, oil, gas and nuclear
• cheap, reliable
• will run out, pollution

Question 14

renewable energy sources

Answer 14

• wind power, solar panels, tidal power

Question 15

conduction

Answer 15

the heat is passed on by collision of particles

Question 16

convection

Answer 16

the heat is passed on by fluid expanding, rising and taking the heat with it

Question 17

insulating materials

Answer 17

Electrons are transferred when objects
- become positively charged when rubbed lose electrons
- become negatively charged when rubbed gain electrons

Question 18

series circuit

Answer 18

• current the same in each component
• adding more resistors increases total resistance because current is reduced

Question 19

parallel circuit

Answer 19

• total current is sum of currents through all components
• the bigger resistant of component the smaller the current passing through
• more resistors decrease resistance because total current is increased

Question 20

internal energy

Answer 20

• when substance is heated its temperature rises the kinetic energy of particles increase
• if it melts or boils the potential energy of particles increase
• pressure of gas on surface is caused by particles of gas hitting the surface

Question 21

pressure

Answer 21

• if temperature of gas in a sealed container is increased the pressure increases because molecules move faster hitting the surface with more force

Question 22

wires

Answer 22

• green/yellow = earth wire
• brown = live wire
• blue = neutral wire

Fuse w earth wire protect from electricution

Question 23

radioactive decay

Answer 23

radioactive substances are unstable and continuously give out radiation.

Question 24

radioactivity

Answer 24

decay that happens with a certain probability

Question 25

alpha radiation

Answer 25

when an atom decays into a new type of atom and emits an alpha particle
2 protons and 2 neutrons

Question 26

Beta radiation

Answer 26

when a neutron turns into a proton and electron

Question 27

Gamma radiation

Answer 27

high energy light with high frequency and short wavelength.

Question 28

Half life of an atom

Answer 28

time taken for half of the radioisotopes in a sample to decay.