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Flashcards in topic 1 (energy) Deck (22)
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1

energy

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

2

types of energy stores (9)

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

3

kinetic energy

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)

4

elastic potential energy

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)

5

GPE

GPE - energy stored in an object above ground

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

6

specific heat capacity

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

7

conduction

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

8

convection

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

9

radiators

radiators - create convection current lubrication and reduces frictional forces

10

power

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))

11

reducing unwanted energy transfers

lubrication - reduces frictional forces
insulation - reduces the rate of energy transfer by heating

12

efficiency

efficiency = useful output energy transfer /total input energy transfer

efficiency = useful power output/total power output

13

renewable energy

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....)

14

non-renewable energy

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 )

15

wind power

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

16

solar cells

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

17

geothermal power

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

18

hydro-electric power

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

19

wave-power

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

20

tidal energy

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

21

bio-fuels

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

22

trends in energy source use

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?)