As an aircraft flies through a cold front, an on-board instrument indicates that the ambient temperature drops at the rate of 0.5°F per minute. Other instruments show an airspeed of 300 knots and a rate of climb of 3500 ft per min. The front is stationary and vertically uniform. Compute the rate of change of temperature with respect to horizontal distance through the cold front.
(a) 0.5°F / 300knots
(b) 0.5°F / 3500ft min
(c) 0.5°F / 300 knots + 3500ft min
(d) 0.5°F / √(300² + 3500²)
