A knight sits on a castle wall during a siege. To while away the time, he notes that boulders catapulted from below land on the top of his wall with a vertical velocity of 7.5 m/s. If he is 34 m above the catapult, what is the initial velocity of the boulders? The acceleration of gravity is 9.8 m/s^2.Answer in units of m/s. Shouldnt the answer be 24.7?