NCERT Class 9 Solutions: Surface Areas and Volumes (Chapter 13) Exercise 13.8 – Part 1

Q-1 Find the volume of a sphere whose radius is

Solution:

1. Radius of the sphere

   So, Volume of the sphere

   • =

   • =

   • =

   • ⁼

2. Radius of the sphere

   Volume of the sphere

• =

• =

• =

Q-2 Find the amount of water displaced by a solid spherical ball of diameter.

Solution:

1. Spherical ball’s diameter is

   Radius

   Amount of water displaced by the spherical ball = Volume of the ball

   • =

   • =

   • =

   • =

2. The spherical ball’s diameter

   Radius

   Amount of water displaced by the spherical ball = Volume of the ball

• =

• =

• =

Q-3 The diameter of a metallic ball is. What is the mass of the ball, if the density of the metal is?

Solution:

• Diameter of the ball

• Radius

Volume of the ball

• =

• =

• =

Density of the metal is

Therefore, mass of the ball