The behavior of a sound wave is affected by the density of the medium, the temperature of the medium and the pressure of the medium if it is a gas. Motion of the medium independent of the sound wave may also affect the way sound propagates.
Yes, you may check-in for your Delta Air Lines (DL) flight with your mobile device starting 24 hours and ending 60 minutes before the scheduled departure time (depending on your departure city and destination) to receive a mobile boarding pass on your mobile device.
You can find out which terminal youâre departing from 24 hours before departure and access gate information 4 hours before by using Online Check-in, Flight Status or the Fly Delta app. Once at JFK, please check airport screens for the most up-to-date details. Cutoff time for checked baggage is 60 minutes before departure.