In a harbour, the wind is blowing at the speed of 72 km/h and the flag on the mast of a boat anchored in the harbour flutters along the N-E direction. If the boat starts moving at a speed of 51 km/h to the north, what is the direction of the flag on the mast of the boat?

Answer –

According to the question, the velocity of the boat is 51 km/h and the velocity of the wind is 72 km/h.

The flag is flapping in the direction of northeast. It indicates that the wind is blowing from the north-east. When the ship starts sailing north, the flag will follow the direction of the wind’s relative velocity in relation to the boat.

According to the diagram, the angle between and is ( 90 + 45 ). So using the following expression, we get –

here,

Therefore, the angle with respect to the east direction = 45.11° – 45° = 0.11°