Class 9 Exam > Class 9 Notes > Extra Documents & Tests for Class 9 > Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics
Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics | Extra Documents & Tests for Class 9 PDF Download
SPHERE
Objects like football, volleyball, throw-ball etc. are said to have the shape of a sphere. In mathematical terms, a sphere is a solid generated by revolving a circle about any of its diameters. Let a thin circular disc of card board with centre O and radius r revolve about its diameter AOB to describe a sphere as shown in figure.
Here, O is called the centre of the sphere and r is radius of the sphere. Also, the line segment AB is a diameter of the sphere
For a solid sphere of radius = r, we have :
SPHERICAL SHELL
The solid enclosed between two concentric spheres is called a spherical shell.
For a spherical shell with external radius = R and internal radius = r, we have :
Question for Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, MathematicsTry yourself: Which of the following statements about a sphere is true?View Solution
HEMISPHERE
When a plane through the centre of a sphere cuts it into two equal parts, then each part is called a hemisphere.
From a solid sphere, the obtained hemisphere is also a solid and it has a base as shown in fig.
For a hemisphere of radius r, we have :
HEMISPHERICAL SHELL
The solid enclosed between two concentric hemispheres is called a hemispherical shell.
For a hemispherical shell of external radius = R and internal radius = r, we have :
Ex.1 Find the surface area of a sphere of diameter 14cm.
Sol. Diameter = 14 cm
Ex.2 Find the radius of sphere whose surface area is 314 cm2. (Use π= 3.14)
Sol. Let r cm be the radius of the sphere whose surface area = 314 cm2
Ex.3 Find the total surface area of a hemisphere of radius 10 cm. (Use π= 3.14)
Sol. r = 10 cm.
∴ Total Surface area of the hemisphere = 3πr2 = 3 x 3.14 x (10)2 = 942 cm2
Ex.4 A hemispherical bowl is made from a metal sheet having thickness 0.3 cm. The inner radius ofthe bowl is 24.7 cm. Find the cost of polishing its outer surface at the rate of Rs. 4 per 100 cm2. (Take π = 3.14)
Sol. The outer radius of the bowl = (24.7 + 0.3) cm, i.e., R = 25 cm
∴ Total outer Surface area of the bowl = 2πr2 = 2 x 3.14 x (25)2 cm2
Cost of polishing the outer surface at the rate of Rs. 
Ex.5 Find the amount of water displaced by a solid spherical ball of diameter 28 cm.
Sol. Diameter = 28 cm
The document Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics | Extra Documents & Tests for Class 9 is a part of the Class 9 Course Extra Documents & Tests for Class 9.
All you need of Class 9 at this link: Class 9
|
1 videos|228 docs|21 tests
|
FAQs on Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics - Extra Documents & Tests for Class 9
| 1. What is the formula for calculating the surface area of a sphere? |  |
Ans. The formula for calculating the surface area of a sphere is 4πr², where r represents the radius of the sphere.
| 2. How is the surface area of a hemisphere different from a sphere? | |
Ans. The surface area of a hemisphere is half of the surface area of a sphere. It can be calculated using the formula 2πr², where r is the radius of the hemisphere.
| 3. Can you explain the concept of surface area in simple terms? | |
Ans. Surface area refers to the total area of all the faces or surfaces of a three-dimensional object. It is measured in square units and helps us understand how much space the object occupies externally.
| 4. How can the surface area of a sphere be useful in real-life applications? | |
Ans. The surface area of a sphere has several practical applications. For example, it can be used to calculate the amount of paint needed to cover a spherical object, estimate the heat transfer rate for a heated or cooled sphere, or determine the amount of material required to create a spherical container.
| 5. Is there a relationship between the radius and the surface area of a sphere? | |
Ans. Yes, there is a direct relationship between the radius and the surface area of a sphere. As the radius increases, the surface area also increases. Conversely, if the radius decreases, the surface area decreases as well. This relationship can be mathematically expressed through the formula for the surface area of a sphere, which includes the radius as a variable.
Related Exams
About this Document
|
5.7K Views |
|
4.96/5 Rating |
|
Dec 24, 2024 Last updated |
Document Description: Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics for Class 9 2024 is part of Extra Documents & Tests for Class 9 preparation.
The notes and questions for Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics have been prepared according to the Class 9 exam syllabus. Information about Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics covers topics
like and Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Example, for Class 9 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises and tests below for Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics.
Introduction of Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics in English is available as part of our Extra Documents & Tests for Class 9
for Class 9 & Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics in Hindi for Extra Documents & Tests for Class 9 course.
Download more important topics related with notes, lectures and mock test series for Class 9
Exam by signing up for free. Class 9: Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics | Extra Documents & Tests for Class 9
Description
Full syllabus notes, lecture & questions for Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics | Extra Documents & Tests for Class 9 - Class 9 | Plus excerises question with solution to help you revise complete syllabus for Extra Documents & Tests for Class 9 | Best notes, free PDF download
Information about Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics
In this doc you can find the meaning of Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics defined & explained in the simplest way possible. Besides explaining types of
Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics theory, EduRev gives you an ample number of questions to practice Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics tests, examples and also practice Class 9
tests
|
Explore Courses for Class 9 exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
Related Searches
video lectures
,Class 9
,mock tests for examination
,Surface area of Sphere and Hemisphere - Surface Areas and Volumes
,study material
,Viva Questions
,Mathematics | Extra Documents & Tests for Class 9
,Extra Questions
,shortcuts and tricks
,Previous Year Questions with Solutions
,past year papers
,Mathematics | Extra Documents & Tests for Class 9
,practice quizzes
,Important questions
,Objective type Questions
,Surface area of Sphere and Hemisphere - Surface Areas and Volumes
,Semester Notes
,Mathematics | Extra Documents & Tests for Class 9
,Surface area of Sphere and Hemisphere - Surface Areas and Volumes
,Free
,MCQs
,Class 9
,Class 9
,ppt
,Sample Paper
,Exam
,Summary
;
Additional Information about Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics for Class 9 Preparation
Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Free PDF Download
The Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics is an invaluable resource that delves deep into the core of the Class 9 exam.
These study notes are curated by experts and cover all the essential topics and concepts, making your preparation more efficient and effective.
With the help of these notes, you can grasp complex subjects quickly, revise important points easily,
and reinforce your understanding of key concepts. The study notes are presented in a concise and easy-to-understand manner,
allowing you to optimize your learning process. Whether you're looking for best-recommended books, sample papers, study material,
or toppers' notes, this PDF has got you covered. Download the Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics now and kickstart your journey towards success in the Class 9 exam.
Importance of Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics
The importance of Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics cannot be overstated, especially for Class 9 aspirants.
This document holds the key to success in the Class 9 exam.
It offers a detailed understanding of the concept, providing invaluable insights into the topic.
By knowing the concepts well in advance, students can plan their preparation effectively.
Utilize this indispensable guide for a well-rounded preparation and achieve your desired results.
Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Notes
Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Notes offer in-depth insights into the specific topic to help you master it with ease.
This comprehensive document covers all aspects related to Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics.
It includes detailed information about the exam syllabus, recommended books, and study materials for a well-rounded preparation.
Practice papers and question papers enable you to assess your progress effectively.
Additionally, the paper analysis provides valuable tips for tackling the exam strategically.
Access to Toppers' notes gives you an edge in understanding complex concepts.
Whether you're a beginner or aiming for advanced proficiency, Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Notes on EduRev are your ultimate resource for success.
Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Class 9 Questions
The "Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics Class 9 Questions" guide is a valuable resource for all aspiring students preparing for the
Class 9 exam. It focuses on providing a wide range of practice questions to help students gauge
their understanding of the exam topics. These questions cover the entire syllabus, ensuring comprehensive preparation.
The guide includes previous years' question papers for students to familiarize themselves with the exam's format and difficulty level.
Additionally, it offers subject-specific question banks, allowing students to focus on weak areas and improve their performance.
Study Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics on the App
Students of Class 9 can study Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics alongwith tests & analysis from the EduRev app,
which will help them while preparing for their exam. Apart from the Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics,
students can also utilize the EduRev App for other study materials such as previous year question papers, syllabus, important questions, etc.
The EduRev App will make your learning easier as you can access it from anywhere you want.
The content of Surface area of Sphere and Hemisphere - Surface Areas and Volumes, Class 9, Mathematics is prepared as per the latest Class 9 syllabus.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup