A cylinder 84 cm long is made of steel. Its external and internal diameters are 10 cm and 8 cm respectively. What is the volume of the steel in the cylinder (in $10^{-3}m^3$ and correct up to three decimal places)?
Answer & explanation
Correct answer: option 3
We know that,
Volume of the cylinder = π (R2 - r2)h
We have,
Height of the cylinder = 84 cm
External diameter = 10 cm
then, External radius of the cylinder = 5 cm
Internal diameter = 8 cm
then, Internal radius of the cylinder = 4 cm
As we know,
\(\frac{22}{7}\) × (52 - 42) × 84 cm3= 22 × 9 × 12 = 2376 cm3 or 2.376 × 10-3 m3
Answer = 2.376