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