Question

A solid iron rectangular block of dimensions 40,12 cm and 11cm is cast into the hollow cylindrical pipe of internal radius 6cm and thickness 2cm. Find the length of the pipe (in cm
).

Answer 1

Answer:

Volume of block =220×120×100 c.m

3

=2640000 cm

3

Let height of hollow cylinder =h

⇒ Volume =πR

2

h−πr

2

h

r=35,R=40

⇒ Volume =πh[40

2

−35

2

]

⇒πh×75×5=2640000

⇒

7

22

×h×375=220×12000

h=

375

70×12000

=2240 cm

=22.4 m.

Answer 2

Volume of block =220×120×100 c.m

3

=2640000 cm

3

Let height of hollow cylinder =h

⇒ Volume =πR

2

h−πr

2

h

r=35,R=40

⇒ Volume =πh[40

2

−35

2

]

⇒πh×75×5=2640000

⇒

7

22

×h×375=220×12000

h=

375

70×12000

=2240 cm

=22.4 m.

ABHINAV. ANSWERD