SP3 Conservation of Energy Flashcards
Give 3 examples of energy stores
Kinetic, thermal, chemical, gravitational potential, elastic potential, electrostatic, magnetic, nuclear
What diagrams show efficiency?
Sankey diagrams
- useful energy on top arrow
- wasted energy on bottom arrow
How can efficiency be increased?
Lubrication reduces energy transferred by friction which is then lost - lubricants reduce the amount of wasted energy
Formula for efficiency
efficiency = useful energy transferred by device / total energy
Define thermal conductivity
how well a material transfers energy by conduction
Ways to reduce unwanted thermal energy loss
1) Some houses have cavity walls, made up of an inner and an outer wall with an air gap in the middle
2) Thicker walls help too
Formula for gravitational potential energy
GPE = m x g x change in height
Formula for kinetic energy
KE = 1/2 x mass x v^2
List the non-renewable energy resources
Fossil fuels and nuclear power plants
Advantages of non-renewable energy resources
- reliable
Disadvantages of non-renewable energy resources
- costly
- acid rain
- oil spillages
- nuclear waste is dangerous
- slowly running out of fossil fuels
List the renewable energy resources
Bio-fuels, wind, solar, hydro-electricity, tides
Summarise wind power
Wind turbine has a generator. As wind blades rotate, generator turns and produces electricity
Summarise solar power
Solar cells are made from materials that use energy transferred by light to create an electric current
Summarise hydro-electricity
Involves flooding a valley by building a dam. Rainwater is then collected and allowed out through turbines that create energy
