• When a quarterback calls a pass play, he knows where his intended receiver is likely to be down the field once the ball is snapped and the play develops. A good quarterback is not only able to see where all of his receivers are, but also know where they are going to be. The quarterback throws the football with a certain speed and velocity, using his experience and control, to get the ball to the exact place where the receiver will be when the receiver jukes his defender and looks up to catch the pass. In Speed and Velocity, an activity from Middle School Science Gateways, students learn about speed and velocity in relation to the movements of hockey pucks and figure skaters.

• A good tackle or block would clearly hurt both football players involved if they weren't wearing so many pads. Even with pads, it's hard not to wince when you see the impact of one moving player on another. In Momentum, a simulation activity from Middle School Science Gateways, students can learn about the role of velocity and mass in creating momentum using a bowling ball and pins. Advanced physics students can learn more about momentum in the following Physics Explorer activities: Momentum and Force and Energy & Work, Momentum & Impulse.
  
  
• When a football player gets tackled, he probably isn't thinking about Sir Isaac Newton and how "for every action, there is an equal and opposite reaction." But sometimes, when you see a big player run into a small player and the small player goes flying, it's hard not to think of Newton. In the Middle School Science Gateways activity, Newton's Third Law of Motion, students learn more about Newton's Third Law of Motion as they work with simulated bumper cars.
  
  
• Perhaps this one is too obvious, but it takes a lot of energy for a 250-pound (plus equipment) football player to play football. It isn't just a game; it's work. And work is an important concept in physics. In the Middle School Science Gateways activity, Work and Power, students learn to define work as a product of force and distance in relation to a horse-drawn wagon and a bicycle. Advanced physics students can learn more about work and energy in the Physics Explorer activities: Energy, Energy & Work, Momentum & Impulse, and Energy in Two-Dimensional Collisions.
  
  
• Whether a kicker punts the football as far downfield as possible on fourth down or tries to win the game in sudden death overtime by kicking a field goal from mid-field, he wants to control the path that the ball takes in the air. Kicks are examples of projectile motion. Advanced physics students can learn more about projectile motion in the following Physics Explorer activities: Projectile Motion: Launch Angle, Launching a Projectile, and More Projectiles.

Think About the Problem
The Middle School Science Gateways and Physics Explorer activities recommended in the "Learn About the Problem" section above do not use football as the real-life example used in their simulations. Encourage your students to make their own connections to the physics in football with the following questions:

1. Why is a football player more likely to be stunned if he is tackled head-on rather than from the rear? If two players of equal mass collided such that their helmets met head-on, would the force of the impact be greater on the offensive or the defensive player?
   
   
2. An object's momentum is found by multiplying its mass times its velocity. Momentum is force applied in a given direction. Who has the greater momentum, a 92-kg fullback or a 127-kg tackle, if both are moving at the same velocity? What would happen if those two players collided head-on at that velocity and didn't stick together (as in a tackle)?
   
   
3. Let's say that a team is 4th and "goal to go" on the opposing team's 1 yard line. The quarterback takes the snap and hands the ball off the a 90-kg halfback, who runs and dives toward the goal line at a velocity of 1.5 meters per second. He is met head-on in the air by a 98-kg linebacker moving at a velocity of 1.0 meters per second. Does the halfback score? Why?
   
   
4. In which of the following plays is a football player likely to "work" harder? Justify your answer using descriptions of the work, force, and distance involved.
   
   
• catching a 20-yard pass (Remember that he has to run from the line of scrimmage downfield to the point where he catches the ball.)


• kicking a punt


• rushing for 3 yards straight up the middle




5. Passes and kicks are examples of a football traveling with projectile motion. The ball leaves the quarterback's throwing arm or the punter's foot with an initial velocity and angle above the plane of the field. In terms of velocity and angle and maximum height of the ball, what's the difference between a lob pass and a bullet pass? How does a punter achieve a greater hang time to allow his teammates to get downfield?
   
   
6. The kicker who kicks extra points and field goals can often make the difference between a win and a loss in a tight football game. What factors must a kicker take into consideration in order to kick a successful field goal? What happens if there is a strong head wind? What changes does a kicker have to make because of where the ball is placed on the field? Do the footballs kicked for field goals usually travel end-over-end or in with a spiral spin?

Painting the Line
Have you wondered how you are able to see the yellow first down line superimposed on the football field — and not on the players uniforms — when you watch a game like the Super Bowl on television? It's more complicated than it looks. Not only does the line need to only appear on the turf, but the line has to change its orientation and perspective as the TV camera moves. Read more about this technology at Marshall Brain's HowStuffWorks.com.

More Links
If football players weren't protected by so many pads, it's certain that there would be a lot more injuries. Read more about How NFL Equipment Works.

Dr. William Bugg of the University of Tennessee Physics Department describes more about the "Fizzicks of Football" in this article from the Metro Pulse.