P1 Flashcards
Describe the 5 energy stores
Chemical- food, fuel etc
Kinetic- moving things
Gravitational potential- anything above the ground
Elastic potential- anything being stretched or pulled
Thermal- heat/ hot things
How can energy be transferred?
By heating, waves, electric current or force when it moves an object
What is the conservation of energy?
Energy cannot be created or destroyed
What is a closed system?
A system where no energy transfers take place out of or into the energy stores of the system
What is work done equal to?
Energy transferred
What is the equation for work done?
Work done (J) = force (N) x distance (m)
Where does dissipated energy usually end up?
Thermal store in the surroundings
What is power?
The rate at which energy is transferred OR the rate at which work is done
How can you calculate efficiency?
useful (energy/power) output / total (energy/power) input
What is the unit for efficiency?
It has no units
What is the equation linking Force, Distance and Work Done?
Work done = Force x distance
W= Fs
What is the equation linking
mass, kinetic energy and speed?
Kinetic energy = 1/2 x mass x speed2
Ek = 1/2mv2
What is the equation linking gravitational potential energy, height, mass and gravitational field strength?
Gravitational potential energy = mass x gravitational field strength x height
Ep=mgh
What is the equation linking energy, time and power?
Power = Energy/time
P=E/t
