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?

`["Assume "pi=22/7]`

 

 

Answer 1

 

Let the radius of the circular end be r.

Height (h) of cylindrical vessel = 1 m

Volume of cylindrical vessel = 15.4 litres = 0.0154 m³

`pir^2h=0.0154m^3`

`(22/7xxr^2xx1)m = 0.0154m^3`

⇒ r = 0.07 m

`"Total surface area of vessel "=2pir(r+h)`

                                            `= [2xx22/7xx0.07(0.07+1)]m^2`

                                             = 0.44 x 1.07 m²

                                             = 0.4708 m²

Therefore, 0.4708 m² of the metal sheet would be required to make the cylindrical vessel.