Physics revision - conservation and dissipation of energy Flashcards
What are 5 examples of energy stores
Chemical, Kinetic, Gravitational potential, Elastic potential, Thermal
How is energy transferred
By heating, by waves, by an electrical current or by a force when it moves an object.
When an object falls and gains speed, what happens to its gravitational potential and kinetic store.
The gravitational potential energy store decreases and the kinetic energy store increases.
What is a closed system
A system where energy can not leave
What is work done
The energy transferred
How is energy wasted
By being transferred to a useless energy store - usually thermal
How can efficiency be improved
By insulating , lubricating and making objects more streamlined.
What is the equation for efficiency
Useful power output
Equation for efficiency = ________________ x 100
Total power input
What are 3 examples of a non renewable energy resource
Coal, oil, (natural) gas
What are 4 examples of a renewable energy resource
The sun, wind, waves, tides
What store is energy transferred to when an object is squashed or stretched
Elastic potential energy store
What energy store does an object have if it’s moving
Kinetic
What does the conservation of energy state
That energy can not be created or destroyed
What is power
The rate of energy transfer
What is the formula to calculate power
Power = Energy transferred
time
