What causes an electric field?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

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?

The junction rule describes the conservation of which quantity? note that this rule applies only to circuits that are in a steady state.