topic 1 (energy)

Question 1

energy

Answer 1

energy can never be used up just transferred this can be by heating or doing work

Question 2

types of energy stores (9)

Answer 2

• GPE -sound energy
• electrical energy -light energy
• elastic potential energy -nuclear energy
• kinetic energy -chemical energy
• heat/thermal energy

Question 3

kinetic energy

Answer 3

kinetic energy - is energy stored in a moving object

KE = 1/2 mv ^2 KE=-kinetic energy (J)
m= mass (kg)
v= velocity (m/s)

Question 4

elastic potential energy

Answer 4

elastic potential energy - is energy stored in a stretched spring

Ee = 1/2 Ke^2 Ee=elastic potential energy (J)
K= spring constant (N/m)
e= extension (m)

Question 5

GPE

Answer 5

GPE - energy stored in an object above ground

Ep=mgh Ep= GPE (J)
m=mass (kg)
g=gravitational field strength (N/kg)

Question 6

specific heat capacity

Answer 6

specific heat capacity - of a substance is is the energy required to raise the temp of 1 kg of a substance by
1 degree C

change in thermal energy= mass x SHC x temp change (degree cel..)
(J) (kg) (J/kg degree C) (d

Question 7

conduction

Answer 7

conduction - is the process where vibrating particles transfer energy to neighbouring particles (it mainly occurs in solids )

Question 8

convection

Answer 8

convection - is where energetic particles move away from hotter to cooler regions ( can happen is gases
and liquids )

Question 9

radiators

Answer 9

radiators - create convection current lubrication and reduces frictional forces

Question 10

power

Answer 10

power is the rate of energy transfer (measured in watts)
P = E/T (energy (J) over time(s))
P = W/T (work done(J) over time (s))

Question 11

reducing unwanted energy transfers

Answer 11

lubrication - reduces frictional forces

insulation - reduces the rate of energy transfer by heating

Question 12

efficiency

Answer 12

efficiency = useful output energy transfer /total input energy transfer

efficiency = useful power output/total power output

Question 13

renewable energy

Answer 13

renewable energy is that will never run out and they damage the environment a lot less then non-renewable energy sources (examples = wind,hydro,bio-fuel….)

Question 14

non-renewable energy

Answer 14

non-renewable energy is energy that will run out one day ,this energy also causes a lot of damage to the environment. ( coal,oil,(natural) gas )

Question 15

wind power

Answer 15

wind power involves lots of wind turbines up in a exposed places like moors or round coasts

Question 16

solar cells

Answer 16

solar cells are expensive but cause no environmental damage ,solar cells generate electrical currents from sunlight

Question 17

geothermal power

Answer 17

geothermal power - energy in underground thermal energy stores this is possible in volcanic areas. the source of much of the energy is the slow decay of various radioactive elements

Question 18

hydro-electric power

Answer 18

hydro-electric power - uses falling water.usually requires flooding of a valley building a big dam, water is then allowed out through a turbine

Question 19

wave-power

Answer 19

wave-power - wave-powered turbines located around the coast like with wind power the main turbines are connected to a generator

Question 20

tidal energy

Answer 20

most common method of tidal energy is the tidal barrages which are big dams built across river estuaries then the water is allowed out of turbines

Question 21

bio-fuels

Answer 21

are made from plants and waste ,they can be solid,liquid or gas and can be burnt to produce electricity or to fun cars

Question 22

trends in energy source use

Answer 22

people want to use more renewable energy sources however the use of renewable energy is limited by reliability ,money and politics (e.g people protesting as to where they are built… visual pollution?)