- #1
shanshan
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Homework Statement
Water si emptying out of a tank at a rate of 4 cubic metres/min. The tank is shaped like an inverted circular cone with a diameter of 8 m at the top. The sides of the cone make a 30 degree with the vertical. Determine the exact value of the rate of change of the water level when the height of the water is 3/4 the height of the cone.
Homework Equations
v=(1/3) (pi) (r^2) (h)
The Attempt at a Solution
v = (1/3) (pi) (3/4(h))^2 (h)
=(3/16)(pi)(h^3)
v'=(9/16)(pi)(h^2)(h')
i don't know where to go from here, as i could use trig to get the height of the tank, but i don't have the height at the time specified. help?