Class 9|Chapter 11|Ex 11.4 |Question 1, 2, 3| SURFACE AREA AND VOLUME

Class 9|Chapter 11|Ex 11.3 |Question 1, 2, 3| SURFACE AREA AND VOLUME
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1. NUMBER SYSTEMS
1.2 Irrational Numbers
1.3 Real Numbers and their Decimal Expansions
1.4 Representing Real Numbers on the Number Line
1.5 Operations on Real Numbers
1.6 Laws of Exponents for Real Numbers
2. POLYNOMIALS
2.2 Polynomials in One Variable
2.3 Zeroes of a Polynomial
2.4 Remainder Theorem
2.5 Factorisation of Polynomials
2.6 Algebraic Identities
3. COORDINATE GEOMETRY
3.2 Cartesian System
3.3 Plotting a Point in the Plane if its Coordinates are given
4. LINEAR EQUATIONS IN TWO VARIABLES
4.2 Linear Equations
4.3 Solution of a Linear Equation
4.4 Graph of a Linear Equation in Two Variables
4.5 Equations of Lines Parallel to x-axis and y-axis
5. INTRODUCTION TO EUCLID’S GEOMETRY
5.1 Introduction
5.2 Euclid’s Definitions, Axioms and Postulates
5.3 Equivalent Versions of Euclid’s Fifth Postulate
6. LINES AND ANGLES
6.2 Basic Terms and Definitions
6.3 Intersecting Lines and Non-intersecting Lines
6.4 Pairs of Angles
6.5 Parallel Lines and a Transversal
6.6 Lines Parallel to the same Line
6.7 Angle Sum Property of a Triangle
7. TRIANGLES
7.2 Congruence of Triangles
7.3 Criteria for Congruence of Triangles
7.4 Some Properties of a Triangle
7.5 Some More Criteria for Congruence of Triangles
7.6 Inequalities in a Triangle
8. QUADRILATERALS
8.2 Angle Sum Property of a Quadrilateral
8.3 Types of Quadrilaterals
8.4 Properties of a Parallelogram
8.5 Another Condition for a Quadrilateral to be a Parallelogram
8.6 The Mid-point Theorem
9. AREAS OF PARALLELOGRAMS AND TRIANGLES
9.2 Figures on the same Base and Between the same Parallels
9.3 Parallelograms on the same Base and
between the same Parallels
9.4 Triangles on the same Base and between
the same Parallels
10. CIRCLES
10.2 Circles and its Related Terms : A Review
10.3 Angle Subtended by a Chord at a Point
10.4 Perpendicular from the Centre to a Chord
10.5 Circle through Three Points
10.6 Equal Chords and their Distances from the Centre
10.7 Angle Subtended by an Arc of a Circle
10.8 Cyclic Quadrilaterals
11. CONSTRUCTIONS
11.2 Basic Constructions
11.3 Some Constructions of Triangles
12. HERON’S FORMULA
12.2 Area of a Triangle – by Heron’s Formula
12.3 Application of Heron’s Formula in finding
Areas of Quadrilaterals
13. SURFACEAREAS AND VOLUMES
13.2 Surface Area of a Cuboid and a Cube
13.3 Surface Area of a Right Circular Cylinder
13.4 Surface Area of a Right Circular Cone
13.5 Surface Area of a Sphere
13.6 Volume of a Cuboid
13.7 Volume of a Cylinder
13.8 Volume of a Right Circular Cone
13.9 Volume of a Sphere
14. STATISTICS
14.2 Collection of Data
14.3 Presentation of Data
14.4 Ggraphical Representation of Data
14.5 Measures of Central Tendency
15. PROBABILITY
15.2 Probability – an Experimental Approach
EXERCISE 11.4
Assume π =
22
7
, unless stated otherwise.
1. Find the volume of a sphere whose radius is
(i) 7 cm (ii) 0.63 m
2. Find the amount of water displaced by a solid spherical ball of diameter
(i) 28 cm (ii) 0.21 m
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 cm3
?
4. 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?
5. How many litres of milk can a hemispherical bowl of diameter 10.5 cm hold?
6. 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.
7. Find the volume of a sphere whose surface area is 154 cm2
.
8. 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, (ii) volume of the air inside the dome.
9. 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, (ii) ratio of S and S′.
10. A capsule of medicine is in the shape of a sphere of diameter 3.5 mm. How much
medicine (in mm3
) is needed to fill this capsule?