6. (17%) Water is being poured at 15 ft3/min into a conical reservoir that is 20 ft deep am has a top radius of 10 ft (Figure 1) (a) How long will it take to ll the empty reservoir? (b) How fast is water level raising when water is 5 ft deep? (C) Is the water level raising faster, or slower when water is deeper? I 1 [Hintz The volume is V = 2rr2h. Based on similar triangle property, we have i = 0 3 1120 l . r = h . Thus, V can be expressed as a function of h alone. As a result, the change of 2 water level, dhx'dt, is related to det which is given as 15 ft3fmin]