P1- conservation and dissipation Flashcards
what are the 9 stores of energy
Sound
Thermal
Elastic
Eelectrical
Light
Potential
Atomic(nuclear)
Chemical
Kinetic
what happens to energy that is lost during transfers
Whenever energy transfers from one store to another, some energy dissipates
definition of elastic potential energy
Elastic potential energy stores = the energy stored when you deform a spring (stretch, squish or bend it)
definition of gravitational potential energy
Gravitational Potential Energy = the amount of energy an object has due to its position (a book on top of a shelf has more GPE compared to a book on the floor).
definition of nuclear energy
Nuclear Energy = energy stored in the nuclei of atoms
definition of chemical energy
Chemical Energy = these stores can be food, fuels, and batteries –> this energy is transferred during a reaction
definition of kinetic energy
Kinetic energy = the energy an object has because it’s moving
definition of thermal energy
Thermal energy = the energy a substance has due to its temperature
what is a closed system
A closed system - an isolated system in which no energy transfers take place into or out of the energy stores of the system (think of it being a closed box where nothing can enter and nothing can leave)
SO, in a CLOSED system, the total energy before any transfers, equals the total energy after any transfers
define ‘work done’
Work done = energy transferred (even as humans, we need energy to do work, otherwise we say we are cba)
Think of a construction worker - to move a substance from point A to B, what two factors determine how much energy they need to put in/how much work they need to do:
the weight of the substance (Force)
the distance they are moving it (distance along the line of action)
what is gravitational potential energy
When an object is moved upwards (its height increases), its GPE increases.
what is the equation for GPE
GPE(J) = W(N) X Δh(m)
or
GPE= m x g x Δh
equation for elastic potential energy
EPE(J) = 1/2 X k(spring constant)(n/m) X extension²(m)
equation for kinetic energy
EK(J) = 1/2 X m(kg) X v²(m/s)
What is useful energy
Useful energy = the energy transferred to where it is wanted in the way it is wanted
