The External radius of a steel pipe is 1.6 cm and its thickness is 1 cm. If 1 cm*3 of steel pipe weighs 20 gms, then find the weight of the steel pipe of length 28 cm.
No options?Strange!sukhman wrote:The External radius of a steel pipe is 1.6 cm and its thickness is 1 cm. If 1 cm*3 of steel pipe weighs 20 gms, then find the weight of the steel pipe of length 28 cm.
It is cylinder, so r=1.6 or it can be average radius i.e r=1.6+0.6=2.2/2=1.1
V= pie r^2 h
=22/7*28*r^2
=88* 1.6^2 or 88* 1.1^2
= 225.28 cubic cm 106.48 cubic cm
So if 1 cubic cm weighs 20gm then
225.28 * 20gms 106.48 * 20gms
4505.6 gms 2129.6 gms
Actually I don't think we need to take the average radius here. So i will go with the former value.
hope i am correct
