On April 15 an airplane takes off at 4:40 P.M. from Belem, Brazil bound for Villamil, Ecuador (in the Galapagos). The plane lands at 8:40 P.M. Villamil local time. The sun sets at 6: 15 P.M. in Belem (local time), and 7:06 P.M. in Villamil (local time). At what time during the flight do the airplane passengers see the sun set?

There is a 3 hour time zone difference between Belem and Villamil, therefore when the plane departed from Belem at 4:40 PM, the time at Villamil was. 4: 40 – 3: 00 = 1: 40PM The plane arrived at Villamil at , and therefore the elapsed time between Belem and Villamil is 8:40 PM -1:40 PM = 7 h 00 min.
Assume that the distance between Belem and Villamil is d , such that the velocity of the plane is:

The time in Villamil when the sun sets in Belem at 6:15 PM is 6 :15 Pm is 6:15-3:00 = 3:15 PM The sun sets in Villamil at 7:06 PM, and therefore the time taken by the sun to move from Belem to Villamil is 7: 06 PM – 3 : 15 PM = 3 h 51 min.
The velocity of the Sun is:

It is important to note that the time difference when the sun sets in Belem and when the plane departed from Belem is 6 : 15 PM – 4: 40 PM = PM = 1 h 35 min Therefore, if the passengers see the sunset after time , the sunset has caught up the plane in time t – 1:35.
When the passengers see the sunset,



Therefore, the passengers in the plane see the sunset 3 h 31 min after the plane leaves the Belem.