Supermassive black holes are believed to be located at the center of many galaxies because a. the rotation curve of the galaxy indicates that 90% of the galaxy is dark matter. b. the orbital speeds of a globular clusters in the galaxy are greater than the speed of light. c. the orbital motion of material near the center is very fast and indicates a very massive core. d. the shape of the bulge in all spiral galaxies can only be supported by a supermassive black hole. e. the spiral structure requires a black hole to maintain the spiral arms.

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole

Most short-period comets do not have randomly oriented orbits because