To determine the arrival time on the west coast, we need to account for the time difference between the eastern United States and the west coast. The west coast is usually 3 hours behind the eastern United States (specifically, Eastern Standard Time).
Given that the flight takes six hours, we need to add the time difference to the departure time.
If the flight departs at 10 AM in the eastern United States, it would be 10 AM Eastern Standard Time (EST).
Adding 6 hours of flight time would bring us to 4 PM EST.
Since the west coast is 3 hours behind the eastern United States, we need to subtract 3 hours from the arrival time.
4 PM minus 3 hours gives us an arrival time of 1 PM on the west coast.
Therefore, if the flight departs at 10 AM from the eastern United States and takes six hours, it would arrive on the west coast at 1 PM.