If the string is pulled down so that the radius is half the original radius, then conservation of angular momentum dictates that the ball must have four times the angular velocity. Using a string through a tube, a mass is moved in a horizontal circle with angular velocity ω. HyperPhysics***** Mechanics ***** RotationĬonservation of linear momentum dictates that when a mass strikes an equal mass at rest and sticks to it, the combination must move at half the velocity, because the product of mass and velocity must remain constant. Moment of Inertia Rotational-Linear Parallels More comparisons between linear and angular motion