Physics and Football BY: Ian Ramdeen, Chris, David, Evan Harrison, and Brent Richardson.

Physics and FootballBY: Ian Ramdeen, Chris, David, Evan Harrison, and Brent Richardson

Football

American football is obviously popular in the U.S., especially in the South.

Did you know that physics can also be found in football such as a football being a projectile, momentum of a player, force applied in a tackle, and forces used in a kick?

Projectile in football

• A projectile is any object that can be thrown.

• In football quarterbacks throw the football for several miles at quick speeds. If a quarterback wants to throw a long pass, then he is going to have to throw at the right angle and right velocity.

Practice Problem

If a quarterback throws a football at 20m/s and at an angle of 60 degrees, how far did he throw the ball?

Formula: R=Vo^2 sin (2 theta)/g

Theta=60 degrees V=20m/s G=9.8m/s^2

Solve for R

Solution: R=20^2 sin (2*60)/9.8

400sin(120)/(9.8)=35.348 meters

Physics Problem

If the same qb throws a football at 25m/s and at an angle of 50 degrees, how far did he throw the ball?

Solution: R=25^2sin2(50)/9.8

63 yards. Wow! What an impressive throw! He gets my MVP vote.

Momentum

Everyone knows that momentum is a measure that is equal to mass times velocity.

This applies to football in this manner because football players of different sizes are running at fast velocities.

Physics Problem

If a 125 kg (275 lb) lineman is running down the field at 9.8 m/s, what is his momentum.

Formula: p=mv

M=125 kg v=9.8 m/s

Find p (momentum)

Solution: p=125 (9.8 m/s)

=1225 kg-m/s

New Problem

If this same lineman runs at 7.5 m/s, what is his momentum?

Solution: 125(7.5)=937.5 kg-m/s

Tacking and Impact

• One of the biggest concepts of physics applied to football is force. A force of a tackle can have huge impacts. If the impact of the tackle is huge, that can lead to a serious injury. If a running back is running with a huge momentum, a sudden tackle can come as a huge shock.

• (Rolando McClain gave this player a huge shock with this strong tackle).

Physics Problem

• If a running back has a momentum of 950 kg-m/s, and the tackle occurs in .6 seconds, what would the force of the tackle be?

• Formula: F=impulse/t

• Impulse (Momentum but written as impulse in this case): 950 kg-m/s

• t=.6 seconds

• Find the Force

• Solution: F=(950 kg-m/s)/ (.6seconds)=1583 N

New Problem

If McClain tackles former Auburn running back Ben Tate in .4 seconds, and his momentum is 1000 kg-m/s, what is the force?

Solution: F=1000/.4=2500N

Physics and kicking

• Physics especially applies to the instance when a placekicker is trying to make a field goal. He has to make adjustments in order to make the attempt. He has to kick the ball at the right angle and has to kick the ball with a good force. He also needs to kick the ball well, so a good acceleration will enable the ball to go through the goal post. A good time while the ball is in the air enables the ball to go through the goal post.

Physics Problem

• A place kicker must kick a football from a point 40 m from the goal and clear the crossbar 3.05 m high, and the ball leaves the ground with a speed of 25 m/s at an angle of 50 degrees to the horizontal at an acceleration of 9.8 m/s. How long does the ball stay in the air?

• Formula: D=ViT+(1/2)A(T^2)

• Given Vi=25m/s A=9.8 m/s D=40m T=?

• 40=25(T)+1/2(9.8)(T^2)

• 4.9(T^2)+25T-40=0 (multiply each side by 10)

• 40=25(T)+4.9(T^2) =-250 +/- the square root of 140900 divided by 98 seconds.

References

http://www.lcse.umn.edu/speces/labs/catapult/index.html

http://entertainment.howstuffworks.com/physics-of-football3.htm

http://answers.yahoo.com/question/index?qid=20080930092439AA1Sgc8