Topic one - energy Flashcards Preview

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Flashcards in Topic one - energy Deck (12):
1

what are the 8 different energy stores

thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic and nuclear

2

what is a closed system

it is a system where neither energy nor mass can enter or leave and therefore the net change in the total energy of a closed system is always zero

3

what is the law of conservation of energy

energy can be transferred usefully, stored or dissipated but can never be created or destroyed

4

what is the definition of conduction

conduction is the process where vibrating particles transfer energy to neighbouring particles

5

what is the definition of convection

convection is where the a region of a gas or liquid is heated and therefore the particles move faster and the space between individual particles increases and therefore the density of the region is decreased. this then causes this region to rise above denser, cooler regions, where, if there is a constant heat source, a convection current could be created.

6

which two key ways could unwanted energy transfers be reduced

lubrication reduces frictional force
insulation reduces the rate of energy transfer by heating

7

how do you work out the elastic potential energy

0.5 x the spring constant (N/m) x extension (m) squared

8

what is specific heat capacity

it is the amount of energy needed to raise the temperature of 1 kg of a substance by 1 degree C

9

how do you work out the change in thermal energy

mass x specific heat capacity x change in temperature

10

while working out energy calculations, which units must always be used

mass - kilograms
temperature - degrees C
for time - seconds
for distance - metres
energy - joules
force - newtons

11

name the seven types of renewable energy sources

wind, solar, geothermal hydroelectric, wave power, tidal barrages and bio-fuels.

12

what are the disadvantages of non renewable fuels

they produce CO2 which contributes to global warming and the greenhouse effect
it can release sulfur dioxide which causes acid rain
open cast mining destroys landscapes and spoils the views
oil spillages cause serous environmental problems
nuclear waste is very dangerous and difficult to dispose of
nuclear power is expensive due to the cost of the power plant and the decommissioning cost
nuclear power has the risk of major catastrophes like Fukushima and Chernobyl, along with the bad reputation surrounding the whole issue