A hemispherical tank is filled with water and has a diameter of 15 feet. If water weighs 62.4 pounds per cubic foot, what is the total weight of the water in a full tank, to the nearest pound?

55107 lb.

Step-by-step explanation:

The Volume of a hemisphere is half the volume of the sphere

Vol. of sphere = 4π/3

Vol of hemisphere = 4π/6 or 2π/3

Diam = 15,    radius = 7.5   and we will use 3.14 for π

V =

  = 2(3.14)(421.875)/3

  = 883.125 cu ft.

883.125(62.4) = 55107 lb.

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°