Lamp A receives 100 J of energy and transfers 12 J of useful energy by light. Lamp B receives 50 J of energy and transfers 8 J of useful energy by light. Which lamp is more efficient?

The discovery of the electron as a subatomic particle was a result of

Would it be correct to say the doppler effect is the apparent change in the speed of a wave due to the motion of the source? be sure to fully explain your position using at least 3 complete content related sentences.

The star nearest to our sun is proxima centauri, at a distance of 4.3 light-years from the sun. how far away, in km, is proxima centauri from the sun?