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.
Yes, the online check-in allows you to check-in and print boarding passes for all your flights before you leave home. So thereâs no hassle with trying to find a printer while youâre away. You can do this from 30 days and up to 2 hours before the scheduled departure of your flight.Any subsequent flights, including your return flight, will also be available for online check-in at the same time (as long as these flights take place within 30 days of when you check in online).nline check-in is a quick and easy way for you to check-in and print your boarding pass at home or at work, saving yourself time and hassle at the airport.