Motion of Two Balls Connected by a Rod

A rod of negligible mass connecting two balls is thrown into the air. The masses of the balls are and , the horizontal and vertical velocities are and , and the angular velocity is . The system exhibits a combination of translational and rotational motion that produces a rippled path. The blue curve follows the center of mass, which moves in a parabolic trajectory. The red curve follows one of the balls as it spins around the center of mass.


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The coordinates of the center of mass of a system of two particles is given by:
and ,
where and are the coordinates of the two masses.
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