Plz answer this question 5. A rectangular sheet of paper 18 into curved of a right
circular cylinder in two ways. Find the ratio of v
Of the cylinders
Fir-a the volume of the metal in a hollow cylinder open atbothends
is 28 cm, thickness 3-5 cm and height 10 cm.
[Hint: External radius — 14 Internal radius —
Volume Of the metal in hollow cylinder 7(14 14 — 105 IOS) 10 cu
7. The radii Of two cylinders are in the ratio 2 • . 3 and their heights are in the ratio 5 3. Ca
the ratio of their volumes.
8. A 20 m deep well with diameter 7 m is dug up and the earth (mitti) from digging is
evenly to form a platform 22 m x 14 m. Determine the height of the platform.
9. A metallic pipe has bore (inner diameter) of 5 cm. The pipe is 2 mm thick all round. Find
weight, in kg, Of 2 m of the pipe if cu cm Of the metal weighs 7-7 gm. (Take It = 3.14)
10. Earth taken out on digging a circular tank of diameter 17.5 m is spread all around the
uniformly to a width Of 4 m to form an embankment Of height 2 m. Calealate the depth of
circular tank correct to 2 decirnal places. (The depth of the tank is uniform
[Hint: Let the depth Of the circular tank be h metres.
The embankment is a circular path, 4 m wide, round the tank and the radius of the
17.5
2
h cu m
Volume Of the earth dug out volume of the tank = — x
255
175
Outer radius of the embankment
2
17.5
22 255
x 2 cu m
V Of the embankment =
2
2
7
= volume of earth dug out
volume of embankment
But,
22 17.5
17.5
2
i, - 225 m.)