A supersonic plane is flying above at a height H = 4 km directly above a small village. The residents hear the sound t = 10 s after the plane has flown above their heads. How would I find the plane (speed of sound is vs = 330 m/s)

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

Can someone explain to me how to do this problem ?

Unpolarized light whose intensity is 1.19 w/ is incident on a polarizer. (a) what is the intensity of the light leaving the polarizer? (b) if the analyzer is set at an angle of = 41.0∘ with respect to the polarizer, what is the intensity of the light that reaches the photocell?