a comet or asteroid impact on the earth is a frequently suggested cause for many of the mass extinctions. for which of the major mass extinctions does the most evidence exist that this was the main trigger for the event?

Who was the first scientist to measure speed as distance over time?

Although longitudinal waves can travel through all media types what is the disadvantage of this type of wave transmission? a) he efficiency of he wave transmission is greatly diminished as the media becomes less dense b) the oscillation of one set of particles has a huge impact on neighboring particles c) particles become too close together as they bump into each other making it more likely to hit other particles down the line

This is the number of complete movements of a wave per second.