The quarterback is trying to throw the ball straight ahead to a receiver who starts his run from a point 20 meter to the left of him. Their aim is that receiver catches the ball 40 m strait ahead of the quarterback at the similar height at which the ball was thrown. The receiver starts his run towards the intended point at t=0 with a constant velocity of 7.7m/s.
a) Find how long should the quarter back wait before he throws the ball if his throw will cause the ball to travel at a speed of 19.8 m/s?
b) Find at what angle above the horizontal should he throw ball?