Describe the path of a light ray that hits a mirror at its vertex.
O A. It is reflected out at exactly the same angle at which it came in,
according to the Law of Reflection.
B. It is reflected back through the focus.
C. It is reflected back parallel to the principal axis.
D. It is absorbed by the mirror.

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.

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.

What is an electric motor? explain its operation. 2-3 sentence