Final answer:
The horizontal distance that the plane has flown as a function of time can be calculated using the equation d = v * t, where v is the velocity of the airplane. In this case, the horizontal distance is directly proportional to time with a constant velocity of 350 mi/h.
Step-by-step explanation:
The horizontal distance d that the plane has flown as a function of time t can be calculated using the formula:
d = v × t
where v is the velocity of the airplane. In this case, the velocity is given as 350 mi/h. So, the equation becomes:
d = 350t
Therefore, the horizontal distance d is directly proportional to time t with a constant velocity of 350 mi/h.