Question

A hollow cylinderical pipe is 21m long. Its inner and outer diameter are 6cm and 10cm respectively.Find the volume of metal used in making the pipe

Answer 1

given :-

height (length) of the pipe = 21cm

inner diameter of the pipe = 6cm

➡ it's inner radius = 6/2 = 3cm

outer diameter of the pipe = 10cm

➡ it's outer radius = 10/2 = 5cm

formula to find the volume of a hollow cylinder is πh(R² - r²). where 'R' is the outer radius since it's greater and 'r' is the inner radius since it's smaller.

we know that a hollow pipe is like a hollow cylinder.

therefore volume of the pipe = πh(R² - r²)

= 22/7 × 21(5² - 3²)

= 22 × 3(25 - 9)

= 66 × 16 $<p></p><p></p><p>= 1056cm³ </p>$