One plane at 520 feet is ascending at a rate of 40 feet per minute, while another plane at 3800 feet is descending at a rate of 120 feet per minute. how long will it take the two planes to be at the same altitude?
Plane A ascending at height = 520 feets
Speed = 40 feet/min
Plane B ascending at height = 3800 feets
Speed = 120 feet/min
Since they are moving towards each other the speeds add up.
So Speed = 40 + 120 = 160
Distance would be difference between the two heights
So Distance = 3800 - 520 = 3280
Time taken for them to get to same altitude t = D / S
Time t = 3280 / 160 = 20.5 minutes
