The Science of Ultimate Frisbee

By: Nate Johnson, and Tyler Livangood

The Question:

What forces, and laws of motion are involved in the game Ultimate Frisbee?

The Research

The Game Ultimate Frisbee is a game that involves throwing a Frisbee to your team mates and try to get the frisbee to the other end of the field while the other team is trying to do the same thing, with the same frisbee. Even though this sport is fun it still goes hand in hand with Science. There are many types of forces of motion in this game, and they each have there place in making the game playable. The main areas that we will look at are Throwing the Frisbee, and Catching the Frisbee. We will look into the physics of what we do and why it works in the game of Ultimate Frisbee.

Throwing the Frisbee

In the video above the guy explains how to do the "Flick Throw" a good move used when someone is blocking you. This one throw demonstrates transfer of momentum in the flick of his wrist. When you flick your wrist your wrist gains momentum( force or speed of movement) that you transfer into the frisbee and because of its shape will glide through the air and accelerate. The definition of "acceleration" is the rate at which velocity changes overtime; an object accelerates it its speed, direction, or both change. This means the frisbee is accelerating for two reasons, it is changing direction and changing speed during its flight.

Air resistance also affects the frisbee during flight, because it creates kinetic friction. You need to put more or less force depending on how far your team mate is if he or she is closer than obviously you would put less force and if they're farther than more force would be required to overcome the friction from the air. Wind is also a big air resistance factor. Because of the light weight of the frisbee and its aerodynamic shape the frisbee gets carried with the wind. Even when your teamate is close to you you have to use more force to overcome the air resistance.

Air flow over a frisbee

The picture above shows us why we throw the frisbee with the dome part facing up. The lower air pressure above the frisbee alows the higher pressure below to create an unblalanced force that pushes it upwards.

Catching the frisbee

Catching the frisbee involves many forces of motion that you would not think about. An object in motion will stay in motion unless acted upon by an unbalanced force, as said in Newton's 1st Law. In this case your hand is the unbalanced force that makes the frisbee stop. When you throw the frisbee it is going to undergo projectile motion, and the person that is trying to catch the frisbee must asume the arc that the frisbee will take. The arc is created because of the force of gravity and the net force on the frisbee as it glides through the air. In the video below you will see how you must predict an object's arc, and how Newton's 3rd Law can be present in ways other than your feet pushing on the ground and the ground pushng back on you.

As you can see in the above video, the person was trying to get to the frisbee when he ran into a golf cart. When he hit the golf cart the golf cart pushed back on him, because for every action force there is an equal and opposite reaction force. The reaction force in this situation would be the person bouncing back off of the golf cart. The third law of motion is every where in Ultimate Frisbee, when you push down on the ground with your legs to jump the ground pushes back on you equally causing you to be able to leap for the frisbee on those tough catches. The frisbee will always try to bounce from your hand when you catch it because of the same reason that you can jump, Newton's 3rd Law.


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