Energy - Forces doing work Flashcards
what happens when a system changes
energy is transferred into or away the system between different objects of different types of energy stores
what are the four ways energy can be transferred
mechanical
electrical
heating
radiation
tell me the energy transfers of the stove and a pan
the system is the camping stove and pan so the energy is transferred from the chemical energy of the stove to the the thermal energy store os the pan and water increasing the temperature
tell me the energy transfer of lifting a box up
the box is the system so work is done against gravity to lift the box up therefore transferring energy to kinetic and gravitational energy store of box
define work done
when a force moves an object through a distance therefore energy is transferred
explain the 2 rules of energy transfers in a closed system
energy can only be stored or transferred to other forms within the system
overall there is no net change to total energy
what does one joule of energy transfer =
one joule of work done
what happens if work done act on direction object is moving
it will gain kinetic energy
what happens if it doesn’t move in direction of object
lost energy
by what energy transfer method is work done
energy transferred mechanically from one store to another
what does a force doing work normally cause
a rise in temperature as energy is dissipated to thermal energy store of moving object and its surroundings
what does friction cause
energy transfer to thermal energy store of object causes temperature ob object to increase and dissipation to surroundings
what is power defined as and its units
the rate of energy transfer in watts
what is one watt equal to
1 joule
what is a moment
the turning effect of a force
