Question
A hollow iron pipe is 21 cm long and its
exterior diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 8 g/cm 3 , then the weight of the pipe isSolution
The pipe can be assumed as hollow cylinder. Thickness = 1 cm Internal radius = 4 - 1 = 3 cm. Volume of the material =`pih(R^2-r^2)` `=22/7xx21xx(4^2-3^2)` `= 22/7xx21xx7` = 462 cm 3 Now, 1cm 3 iron weighs = 8 gm 462 cm 3 iron weighs = 462 × 8 gm ` =(462xx8)/1000kg` = 3.696 kg
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