Answer:
The rate of change of the diver's elevation was 10 53/89 ft./min
Step-by-step explanation:
The given parameters are;
The initial elevation of the diver = 0 feet (Ocean surface level)
The depth to which the diver dove = -59 9/10 feet
The rate at which the diver descended = -18.4 feet/minute
The duration the diver spends at the elevation, t₁ = 12 minutes
The depth to which the diver ascended to = -18 9/10 feet
The total time the diver takes so far in the ocean, [tex]t_{(tot)}[/tex] = 19 1/8 minutes
Therefore, we have;
The time it takes the diver to descend to -59 9/10 feet t₂ = -59 9/10/(-18.4) = 3 47/184 minutes
The duration of the divers ascent = [tex]t_{(tot)}[/tex] - t₁ - t₂ = 19 1/8 - 12 - 3 47/184 = 3 20/23 minutes
The rate of change of the divers elevation in ascent = Distance of elevation/Time
The rate of elevation of the divers elevation in ascent = (-18 9/10 - (-59 9/10))/(3 20/23) = 41/(3 20/23) = 943/89 feet/minute = 10 53/89 feet/minute
The rate of change of the diver's elevation = 10 53/89 ft./min ≈ 10.6 ft./min.