Calculating Work Done: A Physics Question for All Levels

[Geographer]

Hi all, would someone tell me how to calculate work done? We did this ages ago in school, but I can't seem to remember how to do it. There was also other things, but all I can remember is something like force x mass divided by something... sorry. If anyone has the faintest clue what I mean then please help!

You must excuse my lack of knowledge of physics, but I assume this forum is for people of all levels.

 

[Pengwuino]

Work done can be calculated in a number of ways. In general it can be written as:

$$W_{total} = W_{conservative} + W_{non - conservative}$$

This one is basically for when you have more then 1 force acting on a system where certain forces can be considered conservative (gravity for example) and certain forces can be considered non-conservative (friction for example).

$$W = F*\Delta x$$

This is if you have a constant force acting on something for a certain distance. For example, say you have a force of 10N acting upon a block for 10m, you use that to say that 100 J of work have been done on the block.

$$- W = \Delta K + \Delta P$$

This is for when you change something’s potential energy along with its kinetic energy. For example, if you are pushing a block up a hill and you know its initial kinetic and potential energy along with its final kinetic and potential energy, you can determine the work done on the block.

 

[Geographer]

Thanks for your answer, Pengwuino; that has cleared it up for me.

Not exactly a physics question, but I hope someone can point me in the right direction: does anyone know of any active chemisty and geography forums (especially the latter). Most I've come across seem to be defunct with little activity; it's a shame they aren't all like this one!