In a harbour, wind is blowing at the speed of 72km.h and the flag on the mast of a boat anchored in the harbour flutters along the N-E direction. It the boat starts moving at a speed of 51km/h to the north, what is the direction of the flag on the mast of the boat?
The angle between vwand(−vb)=90+45
tanβ=51sin90+4572+51cos90+45
Substituting and solving we get-
tanβ=5150.80=1.0038
β=tan−11.0038=45.11∘
Angle with respect to the east direction =45.11∘−45∘=0.11∘
Hence the flag will flutter almost due east.