Two buses P and Q are moving in opposite directions with velocities 15 m/s and 12 m/s respectively from the same place at the same time. Calculate the relative velocity
of P with respect to Q after 1 second
[Ans: 27 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.