1b.2 work and power Flashcards
amount of work done
the amount that energy is transferred is measured in j
what is work done in a mechanical system
it is the product of force and distance moved in the direction of the force
work done is measured in
(J)
work done =
force (N) x distance moved in the direction of the force (m)
what is the formula for work done when there is an angle between the force and the distance we are acting in
w= f x (change of) s x cos (angle)
power is
the rate of energy transferred
power =
(energy transfer (J) /work done (J) ) overtime taken for energy to be transferred (s) /work to be done (s)
1kW =
1000 W
1 MW =
1000kW
1 GW =
1000MW
1 TW
1000GW
what is efficiency
it is the ability of a machine to transfer energy usefully
what does efficiency =
useful work done / total energy input
what does efficiency flow in a set time equal
usefull energy output/t over total energy input/t
what is energy
the property of an object that gives it the captivity to do work
