Depth of water flowing in a 3 m wide rectangular channel is 2 m. The channel carries a discharge of 12 m3/s. Take g = 9.8 m/s2. The bed width (in m) at contraction, which just causes the critical flow, is _________ without changing the upstream water level. (round off to two decimal places)
An aerial photograph is taken from a flight at a height of 3.5 km above mean sea level, using a camera of focal length 152 mm. If the average ground elevation is 460 m above mean sea level, then the scale of the photograph is
A line between stations P and Q laid on a slope of 1 in 5 was measured as 350 m using a 50 m tape. The tape is known to be short by 0.1 m.
The corrected horizontal length (in m) of the line PQ will be
The bearing of a survey line is N31$$^\circ$$17'. Its azimuth observed from north is __________ deg. (round off to two decimal places)