Question

hey guys... the difference between the innerand outer surfaces of a cylindrical pipe is 88 cm sq .. if the height of the cylindrical pipe is 14 cm and the volume is 176cm sq.. find inner and outer radii of the pipe....... send answer step by step... plz guys kl exam h

Answer 1

apply the formula LSA of cylinder and u will get ans sorry i could not send the solved ans because even I'm having exam

Answer 2

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

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