JEE Main 2019 Mathematics question
A water tank has the shape of an inverted right circular cone, whose semi-vertical angle is . Water is poured into it at a constant rate of 5 cubic meter per minute. Then the rate (in m/min.), at which the level of water is rising at the instant when the depth of water in the tank is 10 m; is:
Answer: (A)
Solution
r = h/2, ; ⇒ .