Question

a cylindrical pipe has external diameter of 75mm. if it is 4.2m long find the area of outer surface.​

Answer 1

Let r,R and h be the inner, outer radii and height of the hollow cylindrical pipe respectively.

Given that 2r=6cm, 2R=8cm, h=28cm

Now, the volume of the pipe, V=π×h×(R+r)(R−r)

∴ Volume, V=616cu.cm

Weight of 1cu.cm of the metal =7gm

Weight of the 616cu.cm of metal =7×616gm

Thus, the weight of the pipe =4.312kg.

solution

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