RI · 2026 · Prelims · Paper 1
Question 3
Part (a) · Find a related rate from a volume function
Part (b) · Link related rates using implicit differentiation
Water is poured at a rate of per minute into an empty container in the form of an open hemisphere with inside radius (see diagram). At time minutes after the start, the radius of the water surface is and the volume of the water in the hemispherical container is , where is the depth of the water. When the depth of the water is ,
find the rate of change of the depth of water,
find the rate of change of the radius of the water surface.