Question

A river 2 m deep and 45 m wide is flowing at the rate of 3 km per hour. Find the amount of water in cubic metres that runs into the sea per minute.

Answer 1

Depth of the river = 2 m

Width of the river = 45 m

Flowing rate of the water = 3 km/h

= `3 xx 1000/60`  ...[∵ 1 km = 1000 m and 1 h = 60 min]

= `3000/60`  

= `300/6`

= 50 m/min

The amount of water into sea per minute

= Depth × Width × Length of water of 1 min

= 2 × 45 × 50

= 4500 m³/min