Question

Find the volume of a copper rod of length 8 cm whose diameter is 1 cm.

Hint:

Always convert diameter to radius before substituting in the cylinder volume formula \(V = \pi r^2 h\).

Answer 1

Step 1: Write the formula for volume of a cylinder.
\[ V = \pi r^2 h \]
Step 2: Substitute given values.
Diameter \(= 1 \, \text{cm} \implies r = \frac{1}{2} \, \text{cm}, \; h = 8 \, \text{cm}\). \[ V = \pi \left(\frac{1}{2}\right)^2 (8) = \pi \times \frac{1}{4} \times 8 = 2\pi \]
Step 3: Conclusion.
Hence, the volume of the copper rod is \(\boxed{2\pi \, \text{cm}^3}\).