An ambulance traveling eastbound at 142.0 km/h with sirens blaring at a frequency of 8.00 x 102 hz passes cars traveling in both the eastbound and westbound directions at 57.0 km/h. (assume the speed of sound is 343 m/s.) (a) what is the frequency observed by the eastbound drivers as the ambulance approaches from behind? hz (b) what is the frequency observed by the eastbound drivers after the artibulance passes thern? hz (c) what is the frequency observed by the westbound drivers as the artıbulance approaches thern? hz (d) what is the frequency observed by the westbound drivers after the ambulance passes thern?

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

In what direction does the medium move relative to the direction of the wave? explain.

Researchers determine that the biodiversity in a woodland region is declining. they identify two major threats to the region's biodiversity, a method to address each threat, and the expected outcome of each method. this information is shown in the table. a) reforestation would not benefit many species because most forest species live on the ground. b) reforestation would take the longest time to be effective because trees take several years to grow. c) biological augmentation would benefit only a few species because is is typically not very effective. d) biological augmentation would take less time to ve effective because it targets the majority of prey species.