In one fortnight of a given month, there was a rainfall of 10 cm in a river valley. If the area of the valley is 97280 km2, show that the total rainfall was approximately equivalent to the addition to the normal water of three rivers each 1072 km long, 75 m wide and 3 m deep
Area of the valley = 97280 km2
If there was a rainfall of 10 cm in the valley then amount of rainfall in the valley = area of the valley × 10 cm
Amount of rainfall in the valley = 97280 km2× 10 cm
Amount of rainfall in one day=9.728×109 * 14
=0.694×109
=6.94× 108 m3
Length of each river, l = 1072 km
= 1072 × 1000 m
= 1072000 m
Breadth of each river, b = 75 m
Depth of each river, h = 3 m
Volume of each river = l × b × h
= 1072000 × 75 × 3 m3
= 2.412 × 108 m3
Volume of three such rivers = 3 × Volume of each river
= 3 × 2.412 × 108 m3
= 7.236 × 108 m3