A jet can travel the 6000 km distance between washington,
d.c. and london in 6 hours with the wind. the return trip against the same wind takes 7 hours 30 minutes. find the speed of the jet in still air and the rate of the wind.
d = r*t is the basic distance equation d = 6000 km t with the tail wind = 6 hr r with the tail wind = speed of the plane + wind speed = s + w t with the head wind = 7.5 hr r with the head wind = speed of the plane - wind speed = s-w (s+w)*6 = 6000 (s-w)*7.5 = 6000 s + w = 1000 s - w = 800 2s = 1800 s = 900 km/h s + w = 1000 w = 100 Check the anwer by calculating the return trip. (900-100) * 7.5 = 800 * 7.5 800 * 7.5 = 6000 km Answer: The rate of the jet in still air is 900 km/h. The rate of the wind is 100 km/hr.
