Question

A solid iron rectangular block of dimensions 2.2m ├Ч1.2m ├Ч1m is cast into a hollow cylindrical pipe of external radius r =35 abd the thickness 5cm find the length of the pipe

Answer 1

given
a rectangle
length=2.2m
breadth=41.2m
height=41m
recast into cylinder
external radius(R)=35cm=35/100=0.35
thickness=5cm=5/100=0.05
a pipe is a hollow cylinder
inner radius(r) =external radius -thickness
=35-5cm=30cm=30/100=0.3
volume (rectangular block)=volume (hollow cylinder)
=>l×b×h=22/7(R×R-r×r)h
=>2.2×41.2×41=22/7 (35×35-30×30)h
h=2.2×41.2×41×7÷22×35×35-30×30
h=1440557.5