A jet aircraft can average 160 miles per hour in calm air. On a trip, the aircraft traveled 600 miles with a tailwind and returned the 600 miles against a headwind of the same speed. If the total round trip took 8 hours, what was the speed of the wind?

Respuesta :

Answer: the speed of the wind is 40 mph

Step-by-step explanation:

Let x represent the speed of the wind.

A jet aircraft can average 160 miles per hour in calm air. On a trip, the aircraft traveled 600 miles with a tailwind. This means that the total speed of the jet aircraft is 160 + x mph

Time = distance/speed

Time taken to cover 600 miles would be

600/(160 + x) - - - - - - - - 1

It returned the 600 miles against a headwind of the same speed. This means that the total speed of the jet aircraft is 160 - x mph

Time taken to return would be

600/(160 - x)

If the total round trip took 8 hours, it means that

600/(160 + x) + 600/(160 - x) = 8

Multiplying through by (160 +x)(160 - x), it becomes

600(160 - x) + 600(160 + x) = 8(160 +x)(160 - x)

96000 - 600x + 96000 + 600x = 8(25600- 160x + 160x - x²)

192000 = 8(25600 - x²)

204800 - 8x² = 192000

204800 - 192000 = 8x²

8x² = 12800

x² =12800/8 = 1600

x = √1600 = ±40

x = 40 mph