Question

A river 3m deep and 40m wide is flowing at the rate of 2km per hour. How much water will fall into the sea in a minute? Detailed answer please (it's for 5marks).

Answer 1

Hey hello friend ,

Here we are given length , width, and height of the river . According to the data it is clear that the river is a cubiodal

The question is how come we get the length well here we are given the rate of flow of the river

i.e. 2km/hr so for one hour it would 2km which is the length of the river .

and breadth (b) is 40 m and the height (h) i.e. depth is 3m

here length given is in 2km i.e. 2000m

 

thus the amount of water that falls is the volume of water that leaves the river

there here river is cubiodal in shape so ,

volume of cubiod is length *breadth *height

therefore volume of river = 2000*40*3=240000

thus in 1 hour i.e. in 60 mins 240000m^3 of water flows

therefore for 1 min =240000/60 m^3 of water will flow

i.e 4000 m^3

we have to convert m^3 to liters

and the relation is 1 m^3=1000l

there 4000m^3=4000000litres

there the amount of water that falls per minute is 4,000,000 liters

Hope this helped u :-)

Answer 2

$\huge{\gray{\boxed{\boxed{\pink{\ulcorner{\mid{\overline{\underline{\bf{Answer:-}}}}}}\mid}}}}$

The river is 3m deep, 40m wide and is flowing at the rate of 2km\hour.

$\sf\red{The \: length \: of \: water \: flow \: in \: 1min= \frac{2000}{60} }$

$\sf\pink{ = \frac{100}{3}m }$

$\sf\gray{Therefore, here \: l = \frac{100}{3}m,b =40m \: and \: h = 3m }$

$\sf\pink{Thus \: required \: volume \: of \: water= \: \frac{100}{3} \times 40 \times 3 }$

$\sf\gray{ = 4000 {m}^{3} }$