1. an airplanes flies a straight course form A to B and back again. the distance between A and B is L and the airplane mantains a constant airspeed V. there is a steady wind with a speed v. a. find an expression. for the total trip time for an arbitrary wind direction. Notice that the trip time is always increased by the presence of a wind in any direction. 2. a pendulum of mass m and length L is released from rest in a horizontal position. a nail a distance d below the pivot causes the mass to move along the path indicated by the dotted line. find the minimum distance d in terms of L such that the mass will swing completely round in the circle.