You and a friend are sitting in the outfield bleachers of a major league baseball park, 140 m from home plate on a day when the temperature is 20 ° C. Your friend is listening to the radio commentary with headphones while watching. The broadcast network has a microphone located 17 m from home plate to pick up the sound as the bat hits the ball. This sound is transferred as an EM wave a distance of 75,000 km by satellite from the ball park to the radio.
(a) When the batter hits a hard line drive, who will hear the "crack" of the bat first, you or your friend, and what is the shortest time interval between the bat hitting the ball and one of you hearing the sound?
(b) How much later does the other person hear the sound?