The westinghouse air brake, first demonstrated successfully in 1868, had been developed to such an extent by 1887 that a train of 50 freight cars traveling at 20 miles per hour could be brought to a standstill in the space of 171 feet, whereas before they required 5 hand breakers over a distance of 1,500 feet for such a train to be stopped.
(a) whereas before they required 5 hand breakers over a distance of 1,500 feet for such a train to be stopped.(b) whereas previously 5 hand breakers operating over a distance of 1,500 feet had been required to stop such a train.(c) but before stopping the train required 5 hand breakers operating over a distance of 1,500 feet.(d) but previously they required 5 hand breakers over a distance of 1,500 feet stopping the train.(e) but before stopping such a train required 5 hand breakers over a distance of 1,500 feet.

Find the volume of the ellipsoid x^2+y^2+5z^2=36.

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz.

In the nineteenth century, gregor mendel first determined some basic rules of genetics that have been observed throughout all types of life. no observations have disproved these basic rules of genetics. charles darwin developed the idea of biological evolution around the same time, but he was unaware of mendel’s discoveries in genetics. over a century later, darwin’s idea of evolution was modified in order to incorporate mendel’s rules of genetics along with the other evidence that darwin had used. what is most likely the relationship between mendel’s rules of genetics and darwin’s idea of biological evolution? a.)mendel’s genetics states laws that are now part of the theory of biological evolution.b.)biological evolution states laws that are part of mendel’s theory of genetics.c.)mendel’s genetics replaced darwin’s entire concept of biological evolution.d.)biological evolution is a law that explains why all genetics exist.