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Dousin12
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<Moderator's note: Moved from a technical forum and thus no template.>
Question: A certain amount of oil on the sea surface can be considered as circular form
and the same thickness throughout its surface. At a certain time, the following are noted
Data: Oil is supplied to the spot at 5m^3/min , the radius is 50 m, the thickness
0.003m and the radius increases (at this time) at 4m/ min.Does the thickness of increase or decrease at the stain at the current time? With what speed does this happen?
My thoughts:
dV/dt=dV/dr * dr/dt , where dr/dt is given and dV/dt is given. However dV/dr I am unsure, coz maybe u should do dV/dh? However. If u use dV/dr, i get that that is equal to (pi*r^2*h)'=2*pi*r*h , and given the data for r, u solve the equation for h? The h i get i take minus the h i had before and that must be the change, however, I get the wrong answer. Where is my thought process wrong?
Question: A certain amount of oil on the sea surface can be considered as circular form
and the same thickness throughout its surface. At a certain time, the following are noted
Data: Oil is supplied to the spot at 5m^3/min , the radius is 50 m, the thickness
0.003m and the radius increases (at this time) at 4m/ min.Does the thickness of increase or decrease at the stain at the current time? With what speed does this happen?
My thoughts:
dV/dt=dV/dr * dr/dt , where dr/dt is given and dV/dt is given. However dV/dr I am unsure, coz maybe u should do dV/dh? However. If u use dV/dr, i get that that is equal to (pi*r^2*h)'=2*pi*r*h , and given the data for r, u solve the equation for h? The h i get i take minus the h i had before and that must be the change, however, I get the wrong answer. Where is my thought process wrong?