Given the positions and masses of a sequence of objects, write a program to compute their center-of-mass, or centroid. The centroid is the average position of the n objects, weighted by mass. If the...

Given the positions and masses of a sequence of objects, write a program to compute their center-of-mass, or centroid. The centroid is the average position of the n objects, weighted by mass. If the positions and masses are given by (xi, yi , mi), then the centroid (x, y, m) is given by