Talk:Energy and work
Jump to navigation
Jump to search
I have a problem with what this teaches. The way I learnt it is this
Work: Applied force x movement in Joule. It's the transferred amount of energy, not stored energy.
Ex: We lift an object of 10kg to 10m high, 1000J of work is done to do this.
Energy: The ability to do work - Not the flow of work. Rather it should be the other way around: Work is the flow of energy.
Ex: To be able to lift the object that high, we need to have at least 1000 J of energy somewhere in our system to be able to do it. If we don't have the energy in the system, we can't do it.
Power: The rate at which work is done and equals the rate at which energy is transferred.
Ex: You need to use 1000kJ, which you do in 10 seconds, meaning you use an average of 100W to lift the object to 10m high.
(all examples are at 100% efficiency of course) This is a stupid image, but it explains it all, better than me: http://i.imgur.com/o3rI3cO.jpg