Question

Total volume of 21 steel balls in a bearing is 88 cubic cm. Find the diameter of each ball.​

Answer 1

Given:

Total volume of 21 steel balls in a bearing is 88 cubic cm

To find:

the diameter of each ball

Solution:

We have given the volume of the 21 steel balls in the bearing is 88 cm³

as we know that the shape of the ball is a sphere so, here we have to consider the volume of the sphere to get the required answer to the question,

so,

the volume of the 21 balls is given by:

• $21(\frac{4}{3} \pi r^{2}) = 88$
• $21(\frac{4}{3} .\frac{22}{7} r^{2}) = 88$
• $r^{2} = 1$
• r = ±1

so there are the two possible values of the radius of the sphere but you should know that the value of the radius can never be negative,

so the radius of the ball will be only 1 cm

as we have

• Diameter = 2×radius
• Diameter = 2×1
• Diameter = 2 cm

Hence,

The diameter of each ball is 2 cm