How does a Frisbee fly?
In addition to lift, there is another strong force that keeps the Frisbee both in the air and straight. This force is called rotational momentum. This rotational momentum keeps the Frisbee from diverting away from its axis of rotation, or the point that the disk is spinning around. In lay terms, it keeps the Frisbee level and straight. Without this momentum, the disk would lean to one side or the other and the flight would turn drastically. But, what is this momentum and how is it made? As an object attached to a single point, or axis of rotation, spins it gets harder for a change in velocity to happen. The angular momentum is higher as the disk spins faster so the amount of torque needed to change the speed of rotation is also higher. A Frisbee has a larger mass on the edge than in the center which creates a large rotational momentum compared to the disk’s weight. This large momentum keeps the Frisbee spinning quickly and level during flight. This fast spinning creates large rotational momentum keeping the Frisbee aligned to the axis of rotation. If the Frisbee did not have such large amounts of spin, it would not be stable and would fall to the ground.