How long does it take (in minutes) for light to reach mercury from the sun, a distance of 6.02 × 107 km?

If a star is moving toward earth, it is

If the wavelength is tripled, while the speed of the wave is held constant, what happens to the frequency?

Two point charges lie on the x axis. a charge of + 2.30 pc is at the origin, and a charge of − 4.50 pc is at x=−11.0cm. what third charge should be placed at x=+26cm so that the total electric field at x=+13.0cm is zero? express your answer to three significant figures and include appropriate units.