Question

A cylindrical metallic pipe is 14 cm long. The difference between
the outside and inside surfaces is 44 cm. If the pipe is made up of
99 cu cm of metal, find the outer and inner radii of the pipe.​

Answer 1

Answer:

Solution:-

Let the outer radius be 'R' and the inner radius be 'r'

Given : Height = `14 cm

Outer Surface Area  - Inner Surface Area = 44 sq cm

⇒ 2πRh - 2πrh = 44

⇒ 2*22/7(R - r) × 14 = 44

⇒ (R - r) = (44 × 7)/(44 × 14)

(R - r) = 1/2 cm  ..........(1)

Now,  

Volume of the metallic pipe = 99 cu cm

πr²h = 99 cu cm

22/7 × (R² - r²) × 14 = 99

22/7 × (R + r) × (R - r) × 14 = 99

Putting the value of (R - r) = 1/2 in the above, we get.

22/7 × (R + r) × 1/2 × 14 = 99

(R + r) = (99 × 2 × 7)/(22 × 14)

(R + r) = 99/22 = 9/2 cm ..............(2)

Adding (1) and (2), we get.

R - r + R + r = 1/2 + 9/2

R + R = 10/2

2R = 5

R = 5/2  

R = 2.5 cm

Now,  

From (2), we get.

2.5 + r = 9/2  

r = 9/2 - 2.5

r = 4/2

r = 2 cm

Hence, the outer radius is 2.5 cm and inner radius is 2 cm

Answer.

hope it helps u

please mark as brainliast answer

Step-by-step explanation: