Problema Solution
Against the wind a commercial airline in South America flew 360 miles in 3 hours. With a tailwind the return trip took 2.5 hours. What was the speed of the plane in still air? What was the speed of the wind?
Answer provided by our tutors
let
d = 360 mi the distance traveled in each direction
t1 = 3 hr traveling against the wind
t2 = 2.5 hr traveling with the wind (tailwind)
w = the speed of the wind
v = the speed of the plane in still air
since speed = distance/time we have:
traveling against the wind the speed of the plane is: v - w
v - w = d/t1
v - w = 360/3
v - w = 120
traveling with the wind the speed of the plane is: v + w
v + w = 360/2.5
v + w = 144
by solving the system of equations:
v - w = 120
v + w = 144
we find:
v = 132 mph
w = 12 mph
click here to see the step by step solution of the system of equations:
the speed of the wind is 12 mph.
the speed of the plane in still air is 132 mph.