Question

1)If the radius of a cylinder is doubled keeping its lateral surface area the
same, then what is its height?


2) A hot water system (Geyser) consists of a cylindrical pipe of length 14 m and
diameter 5 cm. Find the total radiating surface of hot water system.

clear explanation pls​

Answer 1

1--- Let the original radius of a cylinder be (r) and original height of a cylinder be (h).

Original lateral surface area of a cylinder= 2π rh

Radius is doubled then new radius is(R)= 2r

New height of a cylinder= H

New lateral surface area of a cylinder= 2π RH

Original lateral surface area of a cylinder= new lateral surface area of a cylinder

[Given : Lateral surface area of both the cylinders are equal]

2πrh= 2πRH

h= 2H

H= h/2

Hence, the height of a new cylinder is Halved of the original cylinder (h/2).

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2--- for this we find the CSA of the cylinder

radius = 5/2

=2.5

convert into cm=1400

CSA=2πrh

=2×22/7×2.5×1400

=2×22×2.5×200

=44×500

=22000cm²

=220m²

Answer 2

Answer:

answer for the given problem is given