P1/2/3 : Energy Flashcards
What is energy?
The ability to do work.
How can energy be transferred?
Mechanically - when force acts and makes something move
Electrically - when current flows
By heating - Due to temperature change
By radiation - a wave such as light, sound
What is the conservation of energy?
Energy cannot be created or destroyed, it can only be converted to one form to another.
what is work done and the formula?
transferred energy is the wok done by the force.
WD = Force x Distance
What is kinetic energy and the formula?
the work done to ACCELERATE an object is kinetic energy.
KE = 1/2 X MASS X VELOCITY^2
KE=1/2mv^2
What is the change in gravitational potential energy formula?
GPE= mgh
GPE = Mass x strength of gravity x (change in) height
when is GPE gained and lost?
Gained - object is LIFTED
Lost - object is LOWERED
What is energy store in a spring called? What is the energy transfer when releasing a spring?
Elastic Potential Energy
EPE -> KINETIC
What is power and the formula ?
Power is HOW FAST the energy is transferred.
POWER = WD or energy / time (s)
watts = joules/seconds
What is efficiency and the formula ?
Efficiency is the measure of how much USEFUL energy you get out of an object from the energy you PUT IN .
efficiency = (USEFUL ENERGY OUT/ ENERGY IN) X 100
What is heat energy ?
The random kinetic energy of all the particles inside the object. ( type of kinetic energy - joules)
what is heat capacity ?
Measures how much heat is needed to raise an object’s temperature by 1C degree.
What is the most common reason why energy is lost?
Lost to heat
what is SPECIFIC heat capacity ?
Specific heat capacity is the amount of heat energy needed to raise the temperature of 1KG BY 1C DEGREES.
J/Kg/degrees C
what is renewable energy?
Energy from natural sources that us always replenished, so it never runs out
