Work done by a variable force

[deleted647690]

. nvm, I got it haha. I guess if they give you a graph that shows the force changing over time, you should assume force is variable.
The next question also caught me off guard; I wasn't aware that power at constant speed was found with P=F*v. I guess I missed it because I just memorized the equation for power (Power=work/time), and never really understood what power was measuring....

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[Nugester]

. nvm, I got it haha. I guess if they give you a graph that shows the force changing over time, you should assume force is variable.
The next question also caught me off guard; I wasn't aware that power at constant speed was found with P=F*v. I guess I missed it because I just memorized the equation for power (Power=work/time), and never really understood what power was measuring....

It is good to know what things really mean. In this case work/time = (F*d)/t = F*(d/t) = F*v. Or like in Bernoulli's equation pressure = energy over unit volume; P = F/A; F/A * d/d = F*d/V= Work/Volume.

 

[flapjack3d]

Just for future folks, you can estimate the area under the graph to get work. Isn't it C @acetylmandarin ?

 

[deleted647690]

Just for future folks, you can estimate the area under the graph to get work. Isn't it C @acetylmandarin ?

Yeah, it is C

 

[aldol16]

This is where having a little background in calculus can be useful. The general formula for work is W = integral(F*dx). This means that if you plot F versus x, the integral of that graph, or area under the curve in non-calculus terms, gives you work. So if force is variable and you can express it in terms of x, then you can solve the expression for work for any given displacement.