Ahammer taps on the end of a 3.8-m-long metal bar at room temperature. a microphone at the other end of the bar picks up two pulses of sound, one that travels through the metal and one that travels through the air. the pulses are separated in time by 8.80 ms . what is the speed of sound in this metal?

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.