Ex 12.2, 8 - Chapter 12 Class 10 Surface Areas and Volumes

Last updated at April 16, 2024 by Teachoo

Transcript

Ex 12.2, 8
A spherical glass vessel has a cylindrical neck 8 cm long, 2 cm in diameter; the diameter of the spherical part is 8.5 cm. By measuring the amount of water it holds, a child finds its volume to be 345 cm3 . Check whether she is correct, taking the above as the inside measurements, and π= 3.14.
Now,
Volume of vessel
= Volume of sphere + Volume of cylinder
Volume of sphere
Diameter = 8.5 cm
Radius = r = (𝐷𝑖𝑎𝑚𝑒𝑡𝑒𝑟 )/2 = 8.5/2 = 4.25 cm
Volume of sphere = 4/3 𝜋𝑟3
= 4/3×3.14×(4.25)3
= 321.39 cm3
Volume of cylinder
Diameter = 2 cm
Radius = r = 𝐷𝑎𝑖𝑚𝑒𝑡𝑒𝑟/2 = 2/2 = 1 cm
Height of cylinder = h = 8 cm
Volume of cylinder = 𝜋𝑟2ℎ
= 3.14 × (1)2 × (8)
= 3.14 × 8
= 25.12 cm3
Now,
Volume of vessel = Volume of sphere + Volume of cylinder
= 321.39 + 25.12
= 346.51 cm3
Hence, volume obtained by child is incorrect,
correct volume is 346.51 cm3

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.

Hi, it looks like you're using AdBlock :(

Displaying ads are our only source of revenue. To help Teachoo create more content, and view the ad-free version of Teachooo... please purchase Teachoo Black subscription.

Please login to view more pages. It's free :)

Teachoo gives you a better experience when you're logged in. Please login :)

Solve all your doubts with Teachoo Black!

Teachoo answers all your questions if you are a Black user!