Suppose that you gathered a ball of interstellar gas that was equal to the size of earth (a radius of about 6000 km). if this gas has a density of 1 hydrogen atom per cm3, typical of the interstellar medium, how would its mass compare to the mass of a bowling ball (5 or 6 kg)? how about if it had the typical density of the local bubble, about 0.01 atoms per cm3? the volume of a sphere is v = (4/3)πr3.

Anonzero net force acts on a particle and does work. which one of the following statements is true? the kinetic energy of the particle changes, but the speed of the particle does not change. the kinetic energy of the particle does not change, but the speed of the particle does change. the kinetic energy of the particle changes, but the velocity of the particle does not change. the kinetic energy and the speed of the particle change, but the velocity of the particle does not change. the kinetic energy, speed, and velocity of the particle change.