What role does the mass of an object have in determining whether it will be classified as a planet or dwarf planet?

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

An incident ray through the focal point of a spherical mirror will: reflect through the center of curvature. reflect back through the focal point. reflect parallel to the principle axis. reflect the same direction as the incident ray.

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star