An airplane passes over Memphis at a constant speed of 180 kilometers per hour. Another airplane flies over Memphis an hour later traveling the same route. 4 hours after the first plane passed over Memphis, the second plane caught up with it. How fast is the second plane traveling?How fast is the second plane traveling?When the 2nd plane flies over, the first plane has traveled an hour at 180 km/hr. The distance between the two planes is 180 km.
4 hours after the FIRST plan flies over, the 2nd catches it. This means as of this 180 km moment, the 2nd plane has only 3 hours left to catch the first plane. It needs to be traveling 180 km / hr divided by 3 hours faster than the first.
180 km / hr / 3 hr = 60 km more it needs to cover per hour.
so the its speed needs to be 180 km / hr + 60 km / hour
240 km/hrHow fast is the second plane traveling?Four hours after the first plane passed by Memphis, it had travelled a distance of
180 * 4 = 720 km.
The second plane (since it passed over Memphis one hour after the first plane) would have actually flew only 3 hours to catch up with the first plane. Hence, its speed is
720/3 = 240 km/hr.
Hope this helps.
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