John is listening to a horn. He knows the frequency of the horn is 300 Hz when both he and the horn are at rest. If he hears a pitch of 330 Hz, there are clearly several possibilities. True False The distance between John and the horn could be increasing with time. True False Both could be moving and have the same speed. True False Both cannot be moving in the same direction. True False John could be moving towards the horn which is at rest. True False Both could be moving, in opposite directions. True False Both could be moving and have different speeds.