# A calculus problem by Pritam Das

**Calculus**Level pending

Water is being poured into a vessel in the form of an inverted right circular cone of semi vertical angle 45 in such a way that the rate of change of volume at any moment is proportional to the area of the curved surface which is wet at that moment.Initially ,the vessel is full to a height of 2 cm .And after 2 seconds the height becomes 10 cm . What will be the height after 3.5 seconds from the start???