Question

The Huka Falls on the Waikato River is one of New Zealand's most visited natural tourist attractions. On average the river has a flow rate of about 300,000 L/s. At the gorge, the river narrows to 18 m wide and averages 22 m deep.(a) What is the average speed (in m/s) of the river in the gorge?_______m/s.(b) What is the average speed (in m/s) of the water in the river downstream of the falls when it widens to 63 m and its depth increases to an average of 42 m________m/s.

Answer 1

Given,

Flow rate of river is equal to 300,000 L/s.

Width of river = 18 m

and depth of river = 22 m

a) Average speed of river

Q = 300,000 L/s

= 300 m³/s

Q = Av

`v = (Q)/(A)`

`v = (300)/(18 * 22)`

`v = (300)/(396)`

`v = 0.757\ m/s`

b) Average speed when river is widen to 63 m and depth is increased to

`v = (Q)/(A)`

`v = (300)/(63 * 42)`

`v = (300)/(2646)`

`v = 0.113\ m/s`