Question

a boy collects all the rain which falls on a flat rectangular surface of length 6m and breadth 4m and transfer it into the cylindrical vessel of internal radius 20cm. what will be the height of water in the cylindrical vessel if the rainfall is 1cm

Answer 1

rain fall 1 cm in rectangular surface ,
now, rain height = 1 cm
bredth of rectangular surface = 4m
length of rectangular surface = 6 m
system conside just like cuboid ,
where H = 1 cm = 0.01 m
B = 4 m
L = 6 m

now,
volume of rain = volume of cuboid =LBH
=6 x 4 x 0.01 = 0.24 m³

according to question,
volume of rain = volume of cylindrical vessel

0.24 = πr²h

0.24 = 22/7 x (20/100)²h

0.24 = 22/7 x 1/25 x h

h =0.24 x 25 x 7/22 m = 1.9 m

Answer 2

Answer:

Height of water =1.9m

Step-by-step explanation:

Area of rectangle =6×4=24m²

Volume of water fallen on rectangular surface = Area×height

=24m²×0.01m

=0.24m³

This volume is transferred in cylindrical vessel of  internal radius 0.2m.

Let height of water in vessel =h

So Volume of water =πr²h

=(22/7)(0.2)²h

this Volume of water = volume of water fallen on rectangular surface

=0.24m³

So

(22/7)(0.04)h=0.24

h=21/11

=1.9m