A plane travels 2,000 kilometers at a speed of 900 kilometers per hour (kph) with no wind. When a tailwind is present, the plane’s speed increases by x kilometers per hour. The time it takes the plane to travel the same distance with the tailwind, t(x), is defined by the function t(x) = 2,000 / 900 + x . What is the meaning of the y-intercept for this function?