If an airplane is flying at 22,000 feet above sea level and the temperature is 25° cooler than at sea level, what is the temperature at 30,000 feet if the temperature at sea level is -4°?

To determine the temperature at 30,000 feet when given that the temperature at sea level is -4°, and it's 25° cooler at the flying altitude of 22,000 feet, you first need to identify the temperature at 22,000 feet.

Since the temperature is 25° cooler than the sea level temperature, calculate the temperature at 22,000 feet by subtracting 25° from -4°:

-4° (at sea level) - 25° = -29° at 22,000 feet.

Next, to find the temperature at 30,000 feet, you'll need to consider the general lapse rate in the troposphere, which is approximately 2° Celsius per 1,000 feet of altitude. From 22,000 feet to 30,000 feet, which is a 8,000-foot increase, you would multiply the altitude increase by the lapse rate:

8,000 feet * 2°/1,000 feet = 16°.

Now, since the temperature decreases as altitude increases, the temperature at 30,000 feet would be:

-29° (temperature at 22,000 feet) - 16° (temperature drop) = -45