5 Work Energy And Power Flashcards
W=Fx
Work done = force x distance
Work done
Energy transferred
Energy
The capacity to do work
The principle of conservation of energy
The total energy of a closed system remains constant: energy can never be created nor destroyed only transferred from one source to another
Potential
Used to mean hidden or stored
Kinetic energy
The energy associated with an object as a result of its motion
Ek = 1/2 m v^2
Kinetic energy = 1/2 x mass x velocity^2
Gravitational potential energy
The capacity for doing work as a result of an objects position on a gravitational field
Ep = mgh
Gravitational potential energy = mass x gravitational field strength x height
Power
The rate of work done
P = W/t
Power = work /time
Power SI unit
Js^-1 / W
How to calculate efficiency
Useful output energy / total input energy x 100
