- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Metallic spheres of radii 6 cm, 8 cm and 10 cm, respectively, are melted to form a single solid sphere. Find the radius of the resulting sphere.
Given:
Metallic spheres of radii 6 cm, 8 cm and 10 cm, respectively, are melted to form a single solid sphere.
To do:
We have to find the radius of the resulting sphere.
Solution:
The radius of the 1st metallic sphere $= 6\ cm$
This implies,
Volume of the 1st metallic sphere $= \frac{4}{3} \pi (6)^3\ cm^3$
The radius of the 2nd metallic sphere $= 8\ cm$
This implies,
Volume of the 2nd metallic sphere $= \frac{4}{3} \pi(8)^3\ cm^3$
The radius of the 3rd metallic sphere $= 10\ cm$
This implies,
Volume of the 3rd metallic sphere $= \frac{4}{3} \pi(10)^3\ cm^3$
Volume of all three metallic spheres $= \frac{4}{3} \pi(6^3+8^3+10^3)\ cm^3$
Let the three spheres be melted and recast into a new metallic sphere of radius $r$
Therefore,
Volume of the new metallic sphere $= \frac{4}{3} \pi r^3$
This implies,
$\frac{4}{3} \pi(6^{3}+8^{3}+10^{3})=\frac{4}{3} \pi r^{3}$
$6^{3}+8^{3}+10^{3}=r^{3}$
$216+512+1000=r^{3}$
$r^3=1728$
$r=\sqrt[3]{1728}$
$r=12 \mathrm{~cm}$
The radius of the resulting sphere is $12 \mathrm{~cm}$.