Question

the difference between the outside and inside surface of a cylinder kal pipe of 14 cm long is 44 CM square if the pipe is made up of 99 CM cubic of metal find the outer and inner radii 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