A snowball rolls from the roof of a large barn that has a downward slope of 20 °. The roof end is 15.0 m above the ground and the snowball has a speed of 6.00 m / s when abandoned from the roof. At the same moment, a man of 1.90 m tall is 12.0 m from the barn running towards it with speed v, of constant modulus. What must be:

• the highest velocity and
• the lowest velocity for man to be hit by the snowball.