What best describes a lens galaxya. a group if stars that serve as a quick reference to different parts of the skyb. several billion stars arranged in a disk shape that has uneven edgesc. millions of planets are arranged in the shape of a disc with spiraling armsd. billions of stars arranged in the circular pattern with a flattened core

Give an example of a collision in real life. use the law of conservation of energy to describe the transfer of momentum. be sure and discuss the momentum before and after the collision occurs. you will need at least 3 sentences to thoroughly answer this question.

Ais a machine that makes work easier when a single force is applied. a simple machine b compound machine c endangered machine d complex machine

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.