The siren of a fire engine that is driving northward at 30.0 m/s emits a sound of frequency 2000 hz. a truck in front of this fire engine is moving northward at 20.0 m/s. what is the frequency of the siren's sound that the fire engine's driver hears reflected from the back of the truck? ,

as we probably am aware that our atmosphere or air have various levels, each level has different gasses, and each gas has another porousness. at the point when the light originates from lower porousness to higher penetrability, it alters its course. with the goal that implies that when the light originates from the moon to the earth, it alters it's course a lot more occasions. it essentially implies that the state of the light piece of the moon is changed on the earth.

not copied too! hope this !

joke:

h o h o hope you have a merry christmas!