Civil Engineering (CE) Exam  >  Civil Engineering (CE) Questions  >  A trapezoidal channel is 10.0 m wide at the b... Start Learning for Free
A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m is
  • a)
    20.0
  • b)
    3.5
  • c)
    3.1
  • d)
    2.1
Correct answer is option 'D'. Can you explain this answer?
Verified Answer
A trapezoidal channel is 10.0 m wide at the base and has a side slope ...
View all questions of this test
Most Upvoted Answer
A trapezoidal channel is 10.0 m wide at the base and has a side slope ...
's n = 0.013) and carries a discharge of 50 m3/s. Determine the depth of flow and the water surface slope.

Solution:

1. Determine the top width of the trapezoidal channel.

The side slope of 4 horizontal to 3 vertical means that for every 4 units of horizontal distance, the vertical distance is 3 units. Therefore, the height of the trapezoidal channel is:

h = (4/3) x b = (4/3) x 10.0 = 13.33 m

The top width of the trapezoidal channel is:

T = b + 2h/3 = 10.0 + 2(13.33)/3 = 22.22 m

2. Determine the hydraulic radius.

The hydraulic radius is defined as the cross-sectional area of flow divided by the wetted perimeter. For a trapezoidal channel, the cross-sectional area is:

A = (b + zy) y

where z is the side slope, y is the depth of flow, and

y = h - (h/b) x

where x is the distance from the bottom of the channel. Substituting the given values, we have:

A = (10.0 + (4/3) y) y

The wetted perimeter is:

P = b + 2 y / (1 + z2)1/2

Substituting the given values, we have:

P = 10.0 + 2 y / 5

Therefore, the hydraulic radius is:

R = A/P = [(10.0 + (4/3) y) y] / [10.0 + 2 y / 5]

3. Determine the mean velocity.

The mean velocity is given by:

V = Q/A

where Q is the discharge. Substituting the given values, we have:

V = 50 / [(10.0 + (4/3) y) y]

4. Determine the friction slope.

The friction slope is given by:

Sf = (n2 V2 / R)1/3

where n is the Manning's roughness coefficient. Substituting the given values, we have:

Sf = (0.0132 V2 / R)1/3

5. Determine the energy slope.

The energy slope is given by:

Se = Sf + So

where So is the bed slope. Substituting the given values, we have:

Se = Sf + 0.002

6. Determine the depth of flow.

The depth of flow can be determined by using the energy equation:

y = [(Q2 / (g A2)) (1 / (Se2/3)))]1/5

where g is the acceleration due to gravity. Substituting the given values, we have:

y = [(502 / (9.81 x (10.0 + (4/3) y)2)) (1 / ((Sf + 0.002)2/3)))]1/5

This equation cannot be solved algebraically, but it can be solved iteratively using a spreadsheet or a calculator. After several iterations, the depth of flow is found to be:

y = 5.00 m

7. Determine the water surface slope.

The water surface slope can be determined by using the Manning's
Explore Courses for Civil Engineering (CE) exam

Top Courses for Civil Engineering (CE)

A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer?
Question Description
A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer?.
Solutions for A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Civil Engineering (CE). Download more important topics, notes, lectures and mock test series for Civil Engineering (CE) Exam by signing up for free.
Here you can find the meaning of A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer?, a detailed solution for A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? has been provided alongside types of A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A trapezoidal channel is 10.0 m wide at the base and has a side slope of 4 horizontal to 3 vertical. The bed slope is 0.002. The channel is lined with smooth concrete (Manning’s n = 0.012). The hydraulic radius (in m) for a depth of flow of 3.0 m isa)20.0b)3.5c)3.1d)2.1Correct answer is option 'D'. Can you explain this answer? tests, examples and also practice Civil Engineering (CE) tests.
Explore Courses for Civil Engineering (CE) exam

Top Courses for Civil Engineering (CE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev