Bill used candle molds, as shown, to make candles that were perfect cylinders and spheres:
A cylindrical mold is shown, the radius of the top circular section of the cylinder is labeled 2 inches and the height of the cylinder is labeled as 5 inches. On the right side of this mold is a spherical mold. The radius of this spherical mold is labeled as 2 inches.
What is the approximate difference in the amount of wax needed to make a candle from each of these molds? Use π = 3.14. (5 points)
20.82 cubic inches
29.31 cubic inches
56.6 cubic inches
62.8 cubic inches
To find the volume of the cylindrical mold, we use the formula V = πr^2h, where r is the radius and h is the height. Plugging in the values, we get V = 3.14(2^2)(5) = 3.14(4)(5) = 62.8 cubic inches.
To find the volume of the spherical mold, we use the formula V = (4/3)πr^3, where r is the radius. Plugging in the value, we get V = (4/3)(3.14)(2^3) = (4/3)(3.14)(8) = 33.49 cubic inches.
The difference in the amount of wax needed is given by the formula difference = Vcylinder - Vsphere = 62.8 - 33.49 = 29.31 cubic inches.
Therefore, the approximate difference in the amount of wax needed to make a candle from each of these molds is 29.31 cubic inches. So the answer is B) 29.31 cubic inches.