Which is a valid velocity reading for an object? 45 m/s 45 m/s north 0 m/s south 0 m/s

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.