We determine the distance of a Cepheid by We determine the distance of a Cepheid by measuring its parallax. knowing that all Cepheids have about the same luminosity and then applying the inverse square law for light. determining its luminosity from the period-luminosity relation and then applying the inverse square law for light.

How are calculation for velocity and speed different

How to tell if two objects are in thermal equilibrium 1.the objects have the same temperature 2.the objects are the same size 3.the objects are touching each other 4.the objects temperatures are changing

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.