Use Torricelli's principle to find the time it takes to empty a conical tank of circular cross section standing on its apex whose angle is 45° and has an outlet of cross sectional area 1.0cm². The tank is initially full of water and at time t = 0 the outlet is opened and the water flows out. The initial depth of the water in the tank is 2m.

Torricelli's principle: √2gh

Volume of a Cone: V= (1/3) π r² h

I think you set up a differential equation here

dV/dt = -a√2gh I'm not sure if this is right place to start.