Ch 16 Energy Flashcards
Energy
The ability to do work
Measured in
Joules
Dissipation of energy
Energy is changed into a form where it can’t be used again eg heat into air
Types of energy
Kinetic, potential, heat, light, sound, electrical, chemical, and nuclear
Law of conservation of energy
Energy is neither created nor destroyed but can be changed from one change to another
Waste transfers
Energy transfers that aren’t useful
Energy transfer diagram
Shows the useful energy transfers taking place
Sankey diagram
Summarizes all energy transfers taking place
Efficiency formula
Useful energy/ total energy X 100
Power
The rare at which energy is transferred to one form or another
SI of power
Watts (W)
Power formula
Energy / time
Power rating
How much energy is transferred per second in a machine
Unit of electricity
Kilowatt-hour (kWh).
How to reduce energy loss in the home
Use fewer appliances, monitor energy use with energy meters
Insulate house to prevent heat energy dissapiting through walls
