A rescue plane wants to drop supplies to isolated mountain climbers on a rocky ridge 235 m below. The horizontal velocity of the plane is 250 km/h (69.4 m/s). Rescue plane releases the supplies a horizontal distance of 425 m in advance of the mountain climbers. What vertical velocity (up or down) should the supplies be given so that they arrive precisely at the climbers' position (see the figure)? With what speed do the supplies land?