Which of the following terms best describes a group of galaxies? Cluster
Constellation
Solar system
Universe ​

If it takes a planet 2.8 x 10^8 s to orbit a star with a mass of 6.2 x 10^30 kg what is the average distance between the planet and the star

What is a carrier wave and how does it affect what you hear on the radio

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.