physics revision part 2
what are the constant forces?
normal force, friction, tension
what are the long-range forces?
magnestism, gravity
what is force measured in?
newtons
what would have to happen for work to be done?
force must be in direction of movement & there must be movement
what is newtons x metres?
joules
what is potential energy?
stored energy, waiting to be released by conversion into a different energy form
what are the types of potential energy?
gravitational potential energy and elastic potential energy
what are the three types of heat transfer?
radiant heat, conduction and convection
what is radiant heat?
the transfer of heat through electromagnetic waves
what type of heat energy does not require a medium?
radiant heat
what is convection?
the transfer of heat through the bulk motion of a fluid
why does hot fluid rise?
less dense than surrounding cooler fluid therefore rises
what is thermal conduction?
the transfer of heat through a material by atomic vibrations
what are the worst heat conductors?
non-metals
why are metals the best heat conductors?
metals have free electrons which can travel freely through a material, rapidly carrying energy from hotter to cooler regions