Question

Find the amount of empty space within a cylinder containing three solid spheres, where each sphere has a radius of 3 cm. (Volume of a sphere =43πr3) A. 54π cm3 B. 72π cm3 C. 126π cm3 D. 378π cm3

Answer 1

Answer : The correct option is, (A) $54\pi cm^3$

Step-by-step explanation :

First we have to calculate the volume of cylinder.

Formula used:

Volume of cylinder = $\pi r^2h$

where,

r = radius = 3 cm

h = height = 18 cm   (We are assuming that 3 solid spheres stacked to each other = 3 × diameter of each sphere = 3 × 2 × 3 = 18)

Volume of cylinder = $\pi (3cm)^2\times (18cm)$

Volume of cylinder = $162\pi cm^3$

Now  we have to calculate the volume of 3 solid spheres.

Formula used:

Volume of 3 spheres = $3\times \frac{4}{3}\pi r^3$

Volume of 3 spheres = $4\pi r^3$

Volume of 3 spheres = $4\pi (3)^3$

Volume of 3 spheres = $108\pi cm^3$

Now we have to calculate the amount of empty space within a cylinder.

Amount of empty space within a cylinder = Volume of cylinder - Volume of 3 spheres

Amount of empty space within a cylinder = $162\pi cm^3-108\pi cm^3$

Amount of empty space within a cylinder = $54\pi cm^3$

Therefore, the amount of empty space within a cylinder is, $54\pi cm^3$