Question

The outer diameter of a metallic tube is 14cm and thickness of the tube is 1 cm.Find weight of 2 m long tube if the density of the metal is 7 gm/cm cube.​

Answer 1

GIVEN :

• The outer diameter of a metallic tube = 14 cm.

• The thickness of a tube = 1 cm

• Density of a metal = 7 gm/cm³

TO FIND :

• The weight of 2 metre long tube = ?

STEP - BY - STEP EXPLANATION :

=> Outer diameter of a tube = 14cm

=> therefore an outer radius of tube (R) = 7cm

=> Thickness of the tube = 1 cm

=> Inner radius of a tube (r) = 7-1 = 6cm

=> length of the tube (h) = 2 m = 200cm

=> Density of a metal = 7 gm/cm³

Now , we have to find the weight of a tube

We know that –

Weight of the tube = Volume of the metal in tube × Density of the metal

=> Volume of the metal in tube = πR²h - πr²h

=> π (R² - r²) h

$= > \frac{22}{7} ( {7}^{2} - {6}^{2} ) \times 200$

$= > \frac{22}{7} \times 13 \times 200 {cm}^{3}$

weight of the tube = 22/7 × 13 × 200 × 7gm = 57,200 gm.

Hence, weight of tube is 57,200 gm.