Calculus problem! please help! (picture included)
f(x)=4/3 pi r^3
g(x)=4/3 pi r^3
is that the answer? can you show me each steps?:)
No, that's not the answer..
You are looking for a piecewise
find the volume of glass of wine without the cherry
as a function with f(h)=V
then, find how much the cherry displaces the volume
can you write out the steps please?
That would require me to look at parametrization, and I'm too lazy. Instead, @KingGeorge
also, George, can you call other peoples?
Interesting and rather difficult calc problem to be had here @satellite73 @saifoo.khan @amistre64 @myininaya @Hero @AccessDenied @experimentX
by the way, what calc are you taking?
Calc 2, i dont get these problems and i have a few more. ahahaha..
Perhaps the best way to think about this would be as a rotation around the y-axis. If you centered the half-circle of the cup at (0, 0), you could find the volume using rotations.
If it helps you think about it, you could just flip the diagram on its side and rotate around the x-axis instead.
I would appreciate it if you could show me the steps:)
If we flip it so its around the x-axis instead, the big circle would be given by equation \[x^2+y^2=4^2\]And the equation for the circle of the cherry would be \[(x-3)^2+y^2 =1^2\]
Now we need to look at the bounds for the piecewise function we're bound to have. If the liquid is completely covering the cherry, we know that \(0\leq x\leq2\), and if the liquid is only partially covering the cherry, \(2 < x\leq 4\). So those are our two bounds for the upcoming piecewise equation.
Let's start with the easy one. Let \(0\leq x\leq2\). Then the volume of the larger sphere that's filled with liquid would be given by \[\pi \int\limits_h^4 \sqrt{16-x^2}^2\quad dx\]In other terms, \[\pi \int\limits\limits_h^4 16-x^2\quad dx\]Can you evaluate this integral yourself?
yes thank you so much!
There's still more though! That integral is neglecting the cherry that's still in the glass. Fortunately, the cherry is completely covered so we can just subtract by the volume which is \(4\pi/3\). So that's the first piecewise part of the problem.
See, it *was* piecewise! YAHOOO
oh :O ... so I got (h^3/3 -16h + 128/3)π then what do you do..?
IT WAS PIECEWISE, I AM ALWAYYSSS correct...
Now for the second part. This is where the cherry is only partly covered so \(2 < x\leq4\). Also, we'll have to subtract the volume of the cherry before we integrate. Knowing this, we can integrate as follows\[\pi \int\limits_h^4 \sqrt{16-x^2}^2\quad dx - \pi \int\limits_h^4 \sqrt{1-(x-3)^2}^2 \quad dx\]
so it would be π(2h^3/3 -3h^2 -8h + 112/3) and then?
And btw, for the first integral, I'm getting \(-h^3/3 -16h+128/3\)
Times \(\pi\) of course.
the first one h^3/3 is positive.
Oh yes. Of course. Silly me.
are you playing in R^2? instead of R^3?
im getting so confused ... :O
We're rotating about the axis instead of using triple integrals.
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And I'm not getting π(2h^3/3 -3h^2 -8h + 112/3) for the final solution. Rather, I'm getting \(V=\pi(48-24 h+3 h^2)\)
cherry eq = (x-1)^2+y^2 = 2^2 glass eq = (x-4)^2 +y^2 = 4^2 right?
amistre's way will also work, and might actually be an easier way. I've got to leave for a bit now, but good luck. PS. radius of the cherry is 1 not 2.
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