Something interesting here!!!!!!!

[Nikesh]

A funnel has a circular top of diameter 20cm and a height of 30cm. When the depth of the liquid in the funnel is 12cm, the liquid is dripping from the funnel at a rate of 0.2cm3\s. At what rate is the depth of the liquid in the funnel decreasing at this instant? :roll:

 

[Noor]

didn't get it :/

 

[Xenon]

Volume of funnel, V = 1/3 x pi x r^2 x h

dV/dh = (1/3) x pi x r^2

using similar triangle,

12/30 = r/20
r = 20 x 0.4 = 8

when h = 8,
dV/dh = (64/3) x pi

now,

dV/dh = dV/dt x dh/dt

dh/dt = (dV/dh)/(dV/dt) = ((64 x pi)/3)/(0.2)

 

[Nikesh]

i don think ur solution is correct.............plz give me a correct solution

 

[hassam]

 

[Nikesh]

now thats wat i call a complete solution................thanx buddy!!!!

 

[hassam]

if u hv any problem any tym u cn post it