(SP3) Conservation of Energy

Question 1

Law of conservation of energy

Answer 1

Energy cannot be created or destroyed. It can only be transferred from one store to another.

Question 2

Dissipated energy is

Answer 2

the energy that is lost into the surroundings and cannot be used again.

Question 3

Efficiency (formula)

Answer 3

useful energy/total energy

Question 4

Convection

Answer 4

Particles in hot gas and liquid are less dense than the liquid or gas in cold, so it rises into the cold areas. 
- cooling down
- particles slow down 
- less Kinetic energy 
- space between particles decrease
- density increases 
- cold area falls down 
This will repeat until a thermal equilibrium is reached

Question 5

Conduction

Answer 5

Vibrations are passed on between particles that are closely packed together in a solid. The hotter the metal, the more kinetic energy these vibrations have. Wood = insulator; metal = conductor

Question 6

Radiation

Answer 6

Radiation is the only way in which energy can be transferred through vacuum. Heat can be transferred by infrared radiation, which is a type of electromagnetic radiation that involves waves. Infrared radiation is emitted and absorbed by dark objects.

Question 7

Gravitational Potential Energy =

Answer 7

mgh

Question 8

Kinetic Energy (KE) =

Answer 8

1/2 x m x v²

Question 9

Renewable energy (5 sources)

Answer 9

• Solar cells
• Hydroelectricity
• Wind turbines
• Tidal power
• Bio-fuels

Question 10

Non-renewable (2 sources)

Answer 10

• Nuclear fuels

- Fossil fuels