The inner diameter of a cylindrical wooden pipe is 24 cm and its outer

1.	The inner diameter of a cylindrical wooden pipe is 24 cm and its outer diameter is 28 cm. The length of the pipe is 35 cm. Find the mass of the pipe, if 1 cm3 of wood has a mass of 0.6 gm.
Answer» Let r and R be the inner and outer radii of cylindrical pipe. Inner radius of a cylindrical pipe (r) = \(\frac{24}{2}\) = 12 cm Outer radius of a cylindrical pipe (R) = \(\frac{24}{2}\) = 14 cm Height of pipe (h) = length of pipe = 35 cm Mass of pipe = volume x density = π(R² – r²)h = \(\frac{22}{7}\)(14² – 12²)35 = 5720 Mass of pipe is 5720 cm³ Mass of 1 cm³ wood = 0.6 gm Therefore, mass of 5720 cm³ wood = 5720 x 0.6 = 3432 gm = 3.432 kg

The inner diameter of a cylindrical wooden pipe is 24 cm and its outer diameter is 28 cm. The length of the pipe is 35 cm. Find the mass of the pipe, if 1 cm3 of wood has a mass of 0.6 gm.

Answer»

Let r and R be the inner and outer radii of cylindrical pipe.

Inner radius of a cylindrical pipe (r) = \(\frac{24}{2}\) = 12 cm

Outer radius of a cylindrical pipe (R) = \(\frac{24}{2}\) = 14 cm

Height of pipe (h) = length of pipe = 35 cm

Mass of pipe = volume x density = π(R² – r²)h

= \(\frac{22}{7}\)(14² – 12²)35

= 5720

Mass of pipe is 5720 cm³

Mass of 1 cm³ wood = 0.6 gm

Therefore, mass of 5720 cm³ wood = 5720 x 0.6

= 3432 gm

= 3.432 kg