Question

how many lead balls of radius 4cm by melting a lead sphere of diameter 40cm​

Answer 1

Answer:

1 lead ball =4cm radius

Diameter =4*2=8

How many lead sphere will get 40cm diameter =40/8=5

Hope so this will help u mate.....

Answer 2

Answer: 125

Step-by-step explanation:

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

Diameter of lead sphere = 40cm, which means radius is 20cm.

Volume of lead sphere = $\frac{4}{3}\pi (20)^3$

Volume of lead ball = $\frac{4}{3}\pi (4)^3$

The idea here is that if the sphere is melted and cast into smaller balls, the total volume is the same.

Number of lead balls = Volume of lead sphere/Volume of lead balls

So, number of lead balls = $\frac{\frac{4}{3}\pi(20)^3}{\frac{4}{3}\pi(4)^3}$

$=\frac{20^3}{4^3} = (\frac{20}{4})^3 = 5^3 = 125 balls.$