Energy Conservation

Question 1

Energy stores

Answer 1

-kinetic
-chemical
-thermal
-internal
-GPE
-magnetic
-electrostatic
-nuclear

Question 2

Principle of conservation of energy

Answer 2

The total amount of energy in a closed system is constant. Energy cannot be created or destroyed, only converted from one form to another

Question 3

Energy transfer examples

Answer 3

Kettle - electrostatic —> thermal
Log fire - chemical —> thermal
Kicking a ball - KE —> GPE

Question 4

Dissipation of energy

Answer 4

Spreading out into the surroundings (eg. Fiction - dissipation of energy from heat)

Question 5

Reducing energy dissipation

Answer 5

Lubrication - reduces friction
Wheels - reduce friction
Streamlining - reduces air resistance
Thermal insulation - reduces rate thermal energy to lost to surroundings
Low resistance cables - less energy dissipated as heat

Question 6

Energy efficiency

Answer 6

Energy efficiency = useful output energy / total input energy

Question 7

Thermal insulation - housing

Answer 7

-felt loft installation
-cavity wall insulation
-carpets
-double/ triple glazed windows

Question 8

Materials as thermal conductors practical

Answer 8

Independent variable - insulation (eg. Black paper, foil)
Dependant variable - temperature decrease
Control variables - initial temperature, volume of water