Why must we assume that the Sun radiates equally in all directions when we compute the solar luminosity from the solar constant?

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m2 . the wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. how much total electromagnetic energy falls on the area during 1.0 minute

Which of the following is not a characteristic of s waves? a. travel slower than p waves. b. cannot be detected in locations more than 105° from an earthquake’s epicenter. c. travel through solids and liquids. d. only affect coastal regions.

Red light strikes a metal surface and electrons are ejected. if violet light is now used with a 10% greater intensity, what will happen to the ejection rate (number of ejected electrons per second) and the maximum energy of the electrons? a) greater ejection rate; same maximum energyb) same ejection rate; greater maximum energyc) greater ejection rate; greater maximum energyd) same ejection rate; same maximum energye) none of the above answers are correct