A man travelling towards east at 8km/h finds that the wind seems to blow directly from the north On doubling the speed, he finds that it appears to come from the north-east. Find the velocity of the wind.

A car is travelling towards east at 10m*s^(-1) . It takes 10s to change its direction of motion to north and continues with the same magnitude of velocity. Find the magnitude and direction of the average acceleration of the car.

A steamer moves towards north with a velocity v. Smoke from the chimney comes out at 30^@ towards south with respect to the east. If wind is blowing from the west, find the speed of the wind .

An any instant of time, two ships A and B are 70 km apart along a line AB which is directed from north to south . A starts moving towards west at 25km*h^(-1) and at the same time B starts moving towards north at 25km*h^(-1) . Find the distance of closest approach between the two ships and the time required for this.