Question

The thickness of a hollow metallic cylinder is 2 cm it is 70 cm long with outer radius of 14 cm find the volume of the metal used in making the cylinder assuming that it is open at both the ends also find its weight if the metal weighs 8g per cm^3

Answer 1

$\huge{Answer}$

Thickness = 2cm
Length = height = 70cm
Outer radius (R) = 14 cm
Inner radius (r) = 14 - 2 cm
= 12cm
Volume = 2πrh + 2πRh + π (R^2 - r^2)
= 2x 22/7 x 12 x 70 + 2x22/7 x 14 x 70 + 22/7 (14^2 - 12^2)
= 5280 + 6160 + 22/7 [ ( 14+12)(14-12)]
= 11440 + 22/7 x 170
= 11440 + 534.285714
= 11974.2857 cm^3

Weight of metal in 1cm^3 = 8g
Weight of metal in 11974.2857 cm^3 = 11974.2857 x 8 = 95794.2856 g
If, it converts into kg then it would be = 95794.2856/1000
= 95.7942856 kg

Answer 2

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QUESTION :

The thickness of a hollow metallic cylinder is 2 cm it is 70 cm long with outer radius of 14 cm find the volume of the metal used in making the cylinder assuming that it is open at both the ends also find its weight if the metal weighs 8g per cm³.

SOLUTION :

Given :

height of the cylinder = 70cm,outer radius =14cm , inner radius = 12cm and metal weight 8g per cm³.

(i). the volume of outer cylinder =>

πr²h

=> ✓ π = 22/7 ✓

=> 22/7 × 14 × 14 × 70.

=> 22 × 2 × 14 × 70

=> 43,120 cm³

(ii). the volume inner cylinder

=> ( πr²h )

=> 22/7 × 12 × 12 × 70

=> 22 × 12 × 12 ×10

=> 31,680 cm³.

then, the volume of outer cylinder (minus) ( - )
the volume of inner cylinder.

=>. 43,120 - 31,680

=> 11,440 cm³

this volume of metals used in that cylinder.

=> weight = the volume of metal of the cylinder × given weight of each cm³.

=> 11,440 × 8 = 91,520 g

In kg =91,520 /1000

=> 91.520 kg

or we can say that => 91.6 kg