An experiment is performed in deep space with two uniform spheres, one with mass $21\mathrm{.}0$ kg and the other with mass $101\mathrm{.}0$ kg $.$ They have equal radii, r $=0\mathrm{.}35$ m $.$ The spheres are released from rest with their centers a distance $36\mathrm{.}0$ m apart. They accelerate toward each other because of their mutual gravitational attraction. You can ignore all gravitational forces other than that between the two spheres.