Calculating Work Done: A Physics Question for All Levels

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To calculate work done in physics, the formula W = F * Δx is commonly used, where W is work, F is force, and Δx is the distance over which the force is applied. Work can also be expressed as W_total = W_conservative + W_non-conservative, accounting for both conservative forces like gravity and non-conservative forces like friction. Additionally, the relationship W = ΔK + ΔP can be used when considering changes in kinetic and potential energy. The discussion highlights the importance of understanding these formulas for various scenarios in physics. The thread also touches on the need for active forums in chemistry and geography.
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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. :blushing: 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.
 
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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.
 
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!
 
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Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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