P3: Energy And Energy Resources Flashcards
What is conservation of energy?
Energy cannot be created or destroyed it can be only be transfferred from store to another
What is a system?
A system is a chosen object or a group of objects
What is a closed system?
A closed system is an isolated system in which no matter take place into or out of the system
What is energy measured in?
Joules (J)
What is the equation for GPE (gravitational potential energy) ?
GPE = m x g x h
GPE = mass x gravitational field strength x height
What is mass measured in?
Kilograms (kg)
What is gravitational field strength measured in?
N/kg - newtons per kilogram
What is height measure in?
Metres (m)
What is GPE measure in?
Joulse (J)
What is useful energy?
Useful energy is energy transferred to whereit is neeeded and in the form it is wanted
What is wasted energy (unwanted energy)?
Wasted energy that is transferred to the surroundings which become warmer.
This is dissipated energy
What is the formula for energy efficiency?
Energy efficiency = useful output energy / total input energy
What is power?
The rate at which energy is transferred
What is power measured in?
Watts (w)
