Water flows axially up the shaft and out through the two sprinkler arms as sketched in F...

Water flows axially up the shaft and out through the two sprinkler arms as sketched in Fig. P11.1 and as shown in Video V11.2.With the help of the moment-of-momentum equation explain why, at a threshold amount of water flow, the sprinkler arms begin to rotate. What happens when the flowrate increases above this threshold amount?