P1 Flashcards
Name the energy stores
Chemical, electrostatic, magnetic, elastic, nuclear, thermal, GPE, KE
name 4 ways energy can be transfered
Heating, mechanical work, radiation, electrical
What is a closed energy system
where no energy transfers take place in or out of the system. Transfers can happen between energy stores in the system.
what is the formula for work done
work=force/distance
what is the equation for change in GPE
change in GPE = mass x gravitational field strength x change in height.
what makes an object elastic
if it can go back to its original shape after being stretched.
what is the formula for elastic potential energy.
0.5 x k x e squared
k= spring constant
e = extension of spring.
what is the formula for kinetic energy
kinetic energy = 0.5 x m(mass) x v(speed) squared.
what is useful energy
useful energy is energy that’s transferred where it’s wanted in the form it’s wanted.
what is wasted energy
energy that is not transfered usefully
why is energy wasted
friction and heat
what is energy dissapation
where energy will eventually be transfered to the surroundings, heating it up
what is energy supplied to a machine called
input energy
what is energy transfered usefully by a machine called
useful output energy
what is the formula for efficiency
efficiency = useful energy/ total energy x 100
