CBSE - Class 9 Mathematics Surface Area and Volumes Worksheet
EXERCISE 11.4
1.
The diameter of the moon is approximately one-fourth of the diameter of the earth. What fraction of the volume of the earth is the volume of the moon?
2.
A dome of a building is in the form of a hemisphere. From inside, it was white-washed at the cost of ₹ $4989.60$. If the cost of white-washing is ₹ $20$ per square metre, find the (i) inside surface area of the dome,
3.
The diameter of a metallic ball is $4.2$ cm. What is the mass of the ball, if the density of the metal is $8.9$ g per cm$^3$?
4.
Find the volume of a sphere whose surface area is $154$ cm$^2$.
5.
Find the amount of water displaced by a solid spherical ball of diameter (i) $28$ cm
6.
Find the amount of water displaced by a solid spherical ball of diameter (ii) $0.21$ m
7.
A hemispherical tank is made up of an iron sheet $1$ cm thick. If the inner radius is $1$ m, then find the volume of the iron used to make the tank.
8.
How many litres of milk can a hemispherical bowl of diameter $10.5$ cm hold?
9.
A capsule of medicine is in the shape of a sphere of diameter $3.5$ mm. How much medicine (in mm$^3$) is needed to fill this capsule?
10.
Twenty seven solid iron spheres, each of radius $r$ and surface area $S$ are melted to form a sphere with surface area $S'$. Find the (ii) ratio of $S$ and $S'$.
11.
Twenty seven solid iron spheres, each of radius $r$ and surface area $S$ are melted to form a sphere with surface area $S'$. Find the (i) radius $r'$ of the new sphere,
12.
A dome of a building is in the form of a hemisphere. From inside, it was white-washed at the cost of ₹ $4989.60$. If the cost of white-washing is ₹ $20$ per square metre, find the (ii) volume of the air inside the dome.
13.
Find the volume of a sphere whose radius is (ii) $0.63$ m
14.
Find the volume of a sphere whose radius is (i) $7$ cm
