Question

The capacity of a closed cylindrical vessel of height 1 m is 15.4 litres. How many
square metres of metal sheet would be needed to make it?​

Answer 1

Height of the vessel=1m

Capacity of the vessel=15.4 liters

=  

1000

15.4

​  

m  

3

=0.0154m  

3

 

Volume of the cylindrical vessel=πr  

2

h=0.0154

⇒  

7

22

​  

×r  

2

×1=0.0154

r  

2

=  

22

0.0154×7

​  

=0.0049

⇒r=0.07m

Metal sheet needed to make the cylindrical vessel=T.S.A of the cylindrical vessel.

⇒2πr(r+h)=2×  

7

22

​  

×0.07(0.07+1)m  

2

 

=0.4708m  

2

 

∴0.4708m  

2

 of sheet will be required to make the vessel.