Which of the following changes would decrease the force between two charged particles by a factor of 9? A. Decreasing the distance between the particles by a factor of 3 B. Increasing the distance between the particles by a factor of 3 C. Increasing the amount of charge on each particle by a factor of 9 D. Decreasing the amount of charge on one of the particles by a factor of 3

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.