
Scott D. answered 10/10/20
Physics Education Researcher for Science Tutoring
Please watch this video for a full solution! For brevity, my final answers are:
A) 1.529s
B) 19.877m
C) 2.867m
This problem is a "projectile motion" problem; it involves a projectile (a football, in this case) moving through space under the influence of gravity alone. Relevant concepts include kinematics, coordinate systems, two-dimensional vectors, gravity, and acceleration.

Scott D.
I also like to check my work with problems like this using the lab feature of the Projectile Motion PhET, one of many useful online physics simulators: https://phet.colorado.edu/en/simulation/projectile-motion10/10/20