(i) Explain the physical meaning of Reynolds number and Froude
number.
A weir is an obstruction in a channel flow which can be
calibrated to measure the flow rate. The flow discharge Q varies
with gravity acceleration g, weir width b into the paper, and
upstream water height H above the weir crest. If it is known that Q
is proportional to b, use the pi theorem to find a unique
functional relationship Q(g, b, H).