A quarterback throws the football to a stationary receiver who is 15.2 m down the field.

The football is thrown at an initial angle of
42◦
to the ground.
The acceleration of gravity is 9.81 m/s
2

a) At what initial speed must the quarterback throw the ball for it to reach the receiver?
Answer in units of m/s

b) What is the ball’s highest point during its
flight?
Answer in units of m

a. Dx = Vo^2*sin(2A)/g.

Dx = Vo^2*sin84/9.81 = 15.2 m.
0.1014Vo^2 = 15.2
Vo^2 = 149.93
Vo = 12.24 m/s = Initial Velocity.

b. Yo = 12.24*sin42 = 8.193 m/s.
hmax=(V^2-Vo^2)/2g.
hmax = (0-149.82)/-19.6=7.64 m.