Question

a solid iron cuboidal the block of dimension 4.4 m × 2.6 m × 1 m is recast into a hollow cylindrical pipe of internal radius 30 cm and thickness 5 cm. find the length of the pipe

Answer 1

Volume of cuboidal block =4.4x2.6x1=11.44m³
So volume of cuboidal blocks =volume of cylindrical pipe
Volume of cylindrical pipe =pi h (R²+r²)
11.44=pi h (.35²+.30²)
11.44=pi h (.1225+.09)
11.44=pi h *.2125
H=11.44/pi .2125=17.14m

Answer 2

Internal radius, r = 30 cm
Thickness, w = 5 cm
External radius, R = 30 + 5 = 35 cm
Here volume of cuboid = volume of hollow cylinder
440 × 260 ×100 = π(R2 – r2)h
⇒ 440 × 260 × 100 = π(352 – 302)h
⇒ 440 × 260 × 100 = π(325)h
∴ h = 11200 cm = 112 m