One of the important question for the board exam class 10 from
mensuration chapter.This question is from r d sharma class 10 maths.
chapter-16 question number-35 maths r d sharma,mensuration.
In this question we have to find the height of water in the
cylindrical vessel if a rainfall of 1 cm has fallen
given that,
Rain water, which falls on a flat rectangular surface of length
6 m and breadth 4 m is transferred into a cylindrical vessel of
internal radius 20 cm .
Given,
Length of the rectangular surface = 6 m = 600 cm
Breadth of the rectangular surface = 4 m = 400 cm
Height of the perceived rain = 1 cm
So,
Volume of the rectangular surface = length * breadth * height
= 600*400*1 cm3
= 240000 cm3 …………….. (i)
Also given,
Radius of the cylindrical vessel = 20 cm
Let the height of the cylindrical vessel be taken as h cm
We know that,
Volume of the cylindrical vessel = π × r2 × h
= π × 202 × h ……….. (ii)
As all the rain water is transferred to the cylindrical vessel
We can equate both (i) and (ii) for equal volumes,
240000 = π × 202 × h
h = 190.9 cm
Therefore, the height of the cylindrical vessel nearly 191 cm.