Question

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

Answer 1

The dimensions of a cylinder are

Internal diameter = 24cm

Internal radius = 24/12 = 12cm

External diameter = 28cm

External radius = 28/2 = 14cm

Length = 35cm

We know that

Volume of pipe = Volume of cylinder = π (R² – r²) h

By substituting the values

Volume of pipe = ((22/7) × (14² – 12²) × 35)

On further calculation

Volume of pipe = 22 × (196 – 144) × 5

So we get

Volume of pipe = 22 × 52 × 5

By multiplication

Volume of pipe = 5720 cm³

It is given that 1cm³ of wood has a mass of 0.6g

So the mass of pipe = 5720 × 0.6 = 3432g = 3.432kg

Therefore, the mass of pipe is 3.432kg.