Answer:
The difference in the amount of wax needed is 84.78 in³ (84.78 cubic inches)
Step-by-step explanation:
Given
<em>Cylinder</em>
Radius = 3 inches
Height = 7 inches
<em>Sphere</em>
Radius = 3 inches
Required
The difference in the amount of wax needed to make a candle from each of these molds
The quantity or amount required to make a wax of candle from each molds can be calculated by getting the volume of both molds
The volume of a cylinder is calculated using
<em>V₁ = πr²h</em>
where r and h are the radius and the height of the cylinder, respectively.
r = 3 in and h = 7 in
The volume of a sphere is calculated using
where r is the radius of the sphere
r = 3 in
Calculating V₁
V₁ = πr²h
V₁ = π * 3² * 7
V₁ = π * 9 * 7
V₁ = π * 63
V₁ = 63π
Calculating V₂
V₂ = 36π
Having calculated the volume of each molds, the difference in the amount of wax needed can then be calculated.
Difference = V₁ - V₂
Substituting 63π for V₁ and 36π for V₂
Difference = 63π - 36π
Difference = 27π
<em>(Taking π = 3.14)</em>
Difference = 27 * 3.14
Difference = 84.78
Hence, difference in the amount of wax needed is 84.78 in³