Some satellites move around the earth with circular orbits, the distance from the satellite to the ground is 60000km. Calculate the time it takes the satellite to make one revolution around the earth

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.