Energy + Density Flashcards
define kinetic energy
energy stored in moving objects
define elastic potential energy
the energy that is stored within a stretched spring
define gravitational potential energy
the energy stored in an object due to its position above the earth’s surface
define specific heat capacity
the amount of energy required to raise the temperature of 1kg of a substance by 1 degree
define thermal energy
the energy stored due to an objects temperature
define specific latent heat
the amount of energy required to change the state of 1kg if a substance with no change in temperature
define the law of the conservation of energy
energy can be transferred usefully, stored, or dissipated but it can not be created or destroyed
why do solids have a high density?
because the particles are packed closely together and so they have a lot of mass for their volume
why do liquids have a high density?
because the particles are packed together and so liquids have a lot of mass for their volume
why do gases have a low density?
because the particles are very far apart and so gases have a small mass for their volume
define internal energy
the total kinetic energy and potential energy of all the particles that make up a system
what are modern houses built from? (2)
external brick wall
internal breezeblock wall
how do builders correct the cavity in the walls?
they pack the cavity with an insulating material which has a very low thermal conductivity
what other two ways can we reduce the loss of thermal energy in a home?
double-glazed windows - they have very low thermal conductivity
loft insulation - has low thermal conductivity
what are the advantages of fossil fuels (5)
- RELIABLE; always provide energy when we need it
- release a GREAT DEAL OF ENERGY
- ABUNDANT; the world still has plenty of them
- CHEAP
- VERSATILE; can use them for transport, generating electricity and for heating
