Chapter 15 - Energy Transfer and Efficiency Flashcards
What is true about all forms of energy?
It cannot be created or destroyed
What applies to all energy changes?
Conservation of energy
What are some ways which energy can be stored?
GPE, KE, Elastic energy
What is useful energy?
Energy in the place we want it and in the form we want it
What is wasted energy?
Non-useful energy
What eventually happens to wasted energy?
Gets transferred to the surroundings which become warmer
What happens to the form of energy as it spreads out?
Becomes less and less useful
Can a device be 100% efficient?
No
What diagrams can you draw to see the useful and wasted energy?
Sankey diagram
How can you improve the efficiency of a device?
Lubricating moving parts, have lower electrical resistance in wires, streamlining moving parts of objects, reduce noise
What property of the arrow shows the amount of useful or wasted energy?
Width, not length
How can energy loss from homes be reduced?
Cavity walls, loft insulation, double glazing, drought proofing
What value determines the effectiveness of an insulator?
U-value
Is a lower U value a worse insulator?
No
How do solar panels work?
Use suns energy to heat water
