A jumper of mass m=78 kg starts in a crouched position with the jumper's center of mass at a position y1=0 m. Just before the jumper leaves the floor, his or her center of mass is at y2=1 m. From another measurement, you have found that the velocity of the jumper's center of mass has only a y component of v2=2.5 m/s as the jumper's feet leave the floor.