A trapezoidal channel has a bed width of 6 ft and side slope of 3: 2 and conveys water 4.5 ft deep with a mean velocity of 3.5 ft/s. If the channel floor is raised 0.75 fr downstream at the particular...

A trapezoidal channel has a bed width of 6 ft and side slope of 3: 2 and conveys water 4.5 ft deep with a mean velocity of 3.5 ft/s. If the channel floor is raised 0.75 fr downstream at the particular section,

a. What would be the depth at the raised section?

b. What is the maximum permissible change in the floor elevation without changing the upstream condition?