An object’s center of mass moves at a constant velocity along a straight line past the o...

An object’s center of mass moves at a constant velocity along a straight line past the origin. The accompanying figure shows the coordinate system and the line of motion. The dots show positions that are 1 sec apart. Why are the areas in the figure all equal? As in Kepler’s equal area law (see Section 13.6), the line that joins the object’s center of mass to the origin sweeps out equal areas in equal times.