Physicists define the center of mass of two objects (#1 and #2) with masses m1 and m2 at locations x1 and x2 to be xCoM = m1x1 + m2x2 m1 + m2 The velocity of the center of mass is the derivitive with respect to time of the xCoM. Take the derivative of equation (1) with respect to time and write the result in the box below labeled Eq. (2). Hints: x1 and x2 are functions of time. Also vCoM = dxCoM /dt with v1 = dx1/dt and v2 =dx2/dt.