Cheyanne Rimer, Jeremy Massari, William Ortiz, Jordan Cooper, and Duncan Godsey Rotational Mechanics

Torque Torque is produced when a force is applied with leverage. Leverage is the exertion of force by means of a lever or an object used in the manner of a lever. When the force that is being applied is perpendicular, the distance from the turning axis to the point of contact is the lever arm.

Torque Continued Torque is not the same as force. The angle of the force being applied is important. If the force is not at a right angle to the lever arm, then only the perpendicular component of force will contribute to the torque. torque=force(perpendicular angle)X lever arm.

Torque and Center of Gravity When attempting to touch your toes while leaning against a wall, you will find yourself falling over. You fall because there is no base support underneath the center of gravity and because of torque. When the area bounded by your feet is not beneath of center of gravity, that is an example of torque.

Rotational Inertia The resistance of an object to changes in its rotational state of motion is rotational inertia. Rotating objects tend to keep rotating, while nonrotating objects tend to stay nonrotating. Formula: I=mr^2 M=mass, r=distance from a rotational axis. Depending on the object, the formula will change.

Will a hollow or solid cylinder roll faster? The object with the smaller rotational inertia will roll faster. The object with greater rotational inertia will require more time to get rolling. But which has more rotational inertia? The solid or hollow cylinder? The hollow cylinder has a greater rotational inertia therefore the solid cylinder will roll with greater acceleration.

Angular Momentum The product of the momentum of inertia of a body about an axis and its angular velocity at the same axis. When a direction is assigned to rotational speed it is called rotational velocity. The “inertia of rotation” of rotating objects is also called angular momentum.

Angular Momentum Continued Angular momentum=mvr mv is the angular momentum is equal to the magnitude of its linear momentum, while r is the radial distance. Linear momentum= mass X velocity

Conservation of Angular momentum This law states that if no unbalanced external torque acts on a rotating system, the angular momentum of the system is constant. In other words the product of rotational inertia and rotational velocity at one time will be the same as at any other time.