Aparticle which is moving due east at 4ms 3ms. find the change in velocity. changes direction and starts to move due south at 1. rain falls vertically in still air with a constant velocity of 15ms. if a gale suddenly springs up and the wind blows horizontally at 20ms, calculate the resultant velocity of the rain (magnitude and direction) 2. find the magnitude and direction of a 7n and 24n force perpendicular to each other 3.