We first find the volume of the pool, defined as (4/3πr3)/2, where r is the radius of the hemisphere = 0.75 meters. Volume is therefore (4/3π0.753)/2 = 0.8836 cubic meters. To find the time it takes to fill the pool, we divide the volume by the rate at which the pool is being filled:
0.8836 m * second/0.5liters * 1000 liters/m3 = 1767 seconds
The rate at which the water rises = 0.75 meters/1767seconds = 0.042 centimeters per second