Hi, can you please answer this question with explanation?
Worth 20 points ! Please help! ASAP

Heat from the sun reaches earth to a. radiation b. convection c. conduction

Why there is no inductive reactance in dc circuits

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?