Unit Summary

Rotational and Tangential Velocity

 When something spins it has two velocities a tangential velocity and a rotational velocity. The rotational velocity is how fast the rotation of the object is who many times the object rotates in the allotted time. The inner rotation rotates at the same seep that the outer does. The tangential velocity is the strait velocity, that is the velocity that moves only forward. The inner tangential velocity moves slower than the outer tangential velocity.

Rotational Inertia

The harder it is to spin the more rotational inertia the object has. The axis of rotation is where the object spins and the closer the mass is to the axis the easier it is for the object to spin. As well the farther the mass is from the axis of rotation the harder it is to rotate the object. When it is hard to rotate it has a high rotational inertia and if it is easy to spin it has a small rotational inertia.

Conservation of angular momentum

This is the same principle as the conservation of momentum but with rotating objects. The property states that the momentum before is the same as the momentum after. The formula is P=rotational velocity * rotational inertia. One can regulate the inertia and by consequence the velocity will increase or decrease depending on if you increase the inertia or decrease it.

Torque

Torque is the force that causes things to rotate. Torque is made of a force and a lever arm (T=F*Lever Arm). When an item is balanced the counterclockwise and clockwise torque are equal.

Center of Mass/Gravity

The center of mass/gravity is where the force to an object is applied. As long as the center is over the base of support of the object it will not fall over. The lower the center is the harder it is to tip the object and the wider the base of support the harder it is to tip over.

Centripetal/Centrifugal Force

Centrifugal force is made up, it does not exist. The only force acting is the centripetal force which is the force that pulls objects into the center. This force can be the combination of gravity and tension or support, or a wall pushing the object to the center.