Question

water is flowing in a drainage channel of rectangular cross-section. at one point, the width of the channel is 12 m, the depth of water is 6.0 m, and the speed of the flow is 2.5 m/s. at a point downstream, the width has narrowed to 9.0 m, and the depth of water is 8.0 m. what is the speed of the flow at the second point? a) 2.0 m/s b) 3.5 m/s c) 4.0 m/s d) 2.5 m/s e) 3.0 m/s

Answer 1

The speed of flow at the second point in the drainage channel is 2.5 m/s. Therefore, the correct option is d

Step-by-step explanation:

To determine the speed of the flow at the second point, we can use the principle of continuity, which states that the product of the cross-sectional area and the speed of flow remains constant along a streamline.

At the first point, A1 = (width)(depth)

= (12 m)(6.0 m)

= 72 m2.

At the second point, A2 = (width)(depth)

= (9.0 m)(8.0 m)

= 72 m2.

Since the cross-sectional area remains constant, the speed of flow at the second point is also 2.5 m/s, so the correct answer is d) 2.5 m/s.