The diagram shows ned’s movement as he left his house and traveled to different places throughout the day. which reference point should be used to find out how far ned traveled when he went from the pet store to the swimming pool?

The two stars in a certain binary star system move in circular orbits. the first star, alpha, has an orbital speed of 36 km/s. the second star, beta, has an orbital speed of 12 km/s. the orbital period is 137 d. a) what is the mass of the star alpha? b) what is the mass of the star beta?