Question

the difference between the outside and inside the surface area of a cylinder metallic pipe is 14 cm long is 44 square centimetre if the pipe is made of 99 cubic centimetre of metal find the outer and the inner radius of the pipe ​

Answer 1

Answer:R = 2.5 cm and r = 2 cm

Step-by-step explanation:

r= inner radius

R= outer radius

h= height of the metallic pipe = 14 cm

Difference between the Curved surface area of the outer cylinder and Curved surface area of the inner cylinder = 2πRh - 2πrh.

Given:

difference between the outside and inside curved surface area of cylinder= 44 cm² .

so,

2πh( R - r) = 44

2 x 22/ 7 x 14 ( R - r) = 44

R - r = 1 / 2

= 0.5

Given:

the pipe is made up of metal= 99 cm³

Volume of cylindrical metallic pipe = πR²h - πr²h.

so,

22/7 x 14 (R² - r²) = 99

44(R² - r²) = 99

(R² - r²) = 9 / 4

R²-r²= 2.25

( R - r)(R + r) = 2.25

(0.5)(R + r) = 2.25

R + r = 2.25 / 0.5

R + r = 4.5

Adding up both the values we get

2R = 4.5 + 0.5 = 5

R = 2.5 cm and r = 2 cm