Answer

$5.(4$ points$)$ Which of the following statement about a supercritical flow is incorrect?

A$.$ The wave speed is higher than the flow velocity

B$.$ The water depth is smaller than the critical depth

C$.$ For a given discharge, the supercritical flow has higher specific energy than the critical flow

D$.$ A supercritical flow can gradually change to a subcritical flow

Answer

$6.(4$ points$)$ A rectangular open channel with bottom width of $6$ ft $,$ is carrying a flow rate of $30$ cfs $,$ with the depth equal to $1\mathrm{.}0$ ft $.$ Is this a critical, subcritical or supercritical flow

A$.$ Subcritical flow

B$.$ Critical flow

C$.$ Supercritical flow

D$.$ There's not enough information to tell

Answer

$7.(4$ points$)$ An open channel is flowing at a depth of $1\mathrm{.}4$ ft $.$ The normal depth for the present flow rate is $2\mathrm{.}3$ ft and the critical depth is $0\mathrm{.}9$ ft $.$ The surface profile for this gradually varied flow can be categorized as a

A$.$ M$1$ profile

B$.$ S$1$ profile

C$.$ M$2$ profile

D$.$ S$2$ profile

Answer

$8.(4$ points$)$ What is the minimum specific energy for a flow of $60$ cfs in a $10$ ft wide rectangular channel?

A$.1\mathrm{.}038$ ft

B$.1\mathrm{.}557$ ft

C$.2\mathrm{.}038$ ft

D$.2\mathrm{.}557$ ft