Answer:
11.56521 m/s
Explanation:
[tex]A_1[/tex] = Area of first section = [tex]14\times 2[/tex]
[tex]A_2[/tex] = Area of second section = [tex]5\times 0.92[/tex]
[tex]V_1[/tex] = Velocity in first section = 1.9 m/s
[tex]V_2[/tex] = Velocity in second section
From the continuity equation we get
[tex]A_1V_1=A_2V_2\\\Rightarrow V_2=\dfrac{A_1V_1}{A_2}\\\Rightarrow V_2=\dfrac{14\times 2\times 1.9}{5\times 0.92}\\\Rightarrow V_2=11.56521\ m/s[/tex]
The speed of the river through the section of rapids is 11.56521 m/s