water flows through a 6 m wide unfinished rectangular concrete channel with a flow rate of 3 m3/s. head loss can be considered negligible. consider the following scenarios: a. *** the channel is flowing at an upstream depth of 0.20 m when it encounters a 5 cm bump. what is the flow depth over the bump (y2)? does the free surface elevation (y2 z2) rise or fall? b. the channel is flowing at an upstream depth of 0.35 m when it encounters a 12 cm depression. what is the flow depth over the depression? does the free surface elevation rise or fall?