- First Exam -With 100% Verified Solutions-2024

Star A is twice as bright as star B, but also twice as far away. Star A is ___ as luminous as star B {Ans: 8 times. Brightness b changes as L/d^2, so the fact that star A appears twice as bright but is twice as far away means that 2 x 2^2= 8}Does blue light have more energy than red light? {Ans: True. Blue light has more energy than red light.}If planet is in thermal equilibrium, what is energy doing? {Ans: the amount of energy leaving equals the amount of energy arrive. Stuff in equals stuff out.}Star A and star B are two red stars at nearly the same distance from Earth. Star A is many times brighter than star B. What is true of the stars? {Ans: Star A is a red giant, and star B is a main-sequence star. If stars are at the same distance, then brightness indicates luminosity. Since star A is brighter than B but at the same temperature, it must be larger; that is, A is a giant, and B is a dwarf or main-sequence star.}Which is the largest measurement of an angle? {Ans: radian. A radian is