An average person can reach a maximum height of about 65 cm when jumping straight up from a crouched position. during the jump itself, the person's body from the knees up typically rises a distance of around 48 cm. to keep the calculations simple and yet get a reasonable result, assume that the entire body rises this much during the jump. a) with what initial speed does the person leave the ground to reach a height of 65 cm? andb)in terms of this jumper's weight w , what force does the ground exert on him or her during the jump?