Question

outer diamter of a metalic pipe is 14cm & its thickness is 1 cm. If the density of metal is 7gm/cm3 find the weight of 5m long pipe.

Answer 1

Answer

Step-by-step explanation:

Answer 2

outer radius( R ) = 14÷2=7cm
inner radius(r ) = 7-1 = 6cm (because thickness =1cm)
height of pipe = 5 m = 500cm
weight = volume of pipe × density
= πh(R^2 - r^2 ) × 7gm/cm^3
= 22/7 ×500 × (7^2 - 6^2) × 7gm
= 11000× (49 - 36 ) = 11000× 13
= 143000 gm

What I have done is found out the weight in one step. You can also calculate both volumes separately and subtract them i.e. ( πR^2h - πr^2h ) and then multiply it with density for better understanding.

Answer is 143000 gms