posted by Bob .
Tom Brady (the Patriots’ quarterback) throws a football – at a speed of 30 mph at an angle of 50 degrees to the horizontal – toward an intended receiver 20 yd straight downfield behind the goal-line. The pass is released 7.5 ft above the ground. Assume that the receiver is stationary, is isolated and that he can catch the ball from the ground (a shoestring catch) up to a height of 7 ft when the ball arrives at his position. Will the pass be completed? If not will it be short or long? If the conditions (launch height, distance to receiver, height for catch) are exactly the same but the quarterback can only launch the football at 60 degrees to the horizontal (over the outstretched arms of a left guard) what is the range of speeds (accurate to 3 significant digits) he must give the ball at launch so as to make a completion?