GEN PHYS 1 | Rotational Motion

Moment of Inertia

• resistance to rotational acceleration

• equivalent to mass in translational motion

• affected by how the mass is distributed in relation to the axis

Angular Displacement

• equivalent to displacement in translational motion

• direction is along rotation axis

• has a unit of rad

Angular Velocity

• equivalent to velocity in translational motion

• direction is along rotation axis

Angular Acceleration

• equivalent to acceleration in translational motion

• is along the axis of the change in angular velocity

Torque

• equivalent of force in translational motion

• is zero if the force passes through the axis of rotation or if the angle between and is 0° or 180°

• measured in Newton-meters (N • m)

• perpendicular to the plane formed by force and the distance from the pivot

• is = 0 if the angle between r and F is 0º or 180º

Right Hand Rule

• Curl the fingers of your right hand in the direction of rotation.

• Your thumb points along the vector direction of the rotation axis.

Angular Momentum

• equivalent to momentum in translational motion

• parallel to angular velocity vector