Question

A shot putt is a metallic sphere of radius 4.9 cm. if the density of the metal is 7.8 g per cm³.
find the mass of the shot putt

Answer 1

➲ Mass of shot putt = 3.85 kg

Step-by-step explanation:

Given:

• Radius of shot putt is 4.9 cm.
• Density of metal is 7.8 g / cm³.

To Find:

• What is the mass of the shot putt ?

Formula to be used:

• Volume of sphere = 4/3πr³
• Mass = Density x Volume

Solution: Taking π = 22/7

$\implies{\rm }$ 4/3 x 22/7 x (4.9)³ cm³

$\implies{\rm }$ 88/21 x 4.9 x 4.9 x 4.9 cm³

$\implies{\rm }$ 88/21 x 117.649 cm³

$\implies{\rm }$ 88 x 5.602 cm³

$\implies{\rm }$ 493 cm³ ( approx )

Since, Mass of 1 cm³ of metal = 7.8 g

∴ Mass of 493 g = 493 g x 7.8

➱ Mass of shot putt = 3845.44 g

• Changing in KG •

➱ 1 kg = 1000 g so,

➱ 3845.44 g = 3845.44/1000 = 3.85 kg