Since we have that every thousand feet the temperature drops by 3°, and the starting altitude (Sea level) is at 0 meters but with a temperature of 53°, we solve as follows:
*First we determine the decrease in temperature if, and since it behaves linearly we will have that at 30000ft the total drop in temperature is of:
[tex]d=\frac{30000\cdot(-3)}{1000}\Rightarrow d=-90[/tex]So, when the place climbs 30 000 ft there is a drop of 90°. Now, we subtract 90° from 53° and we will get the temperature when the plane reaches 30000ft, that is:
[tex]53-90=-37[/tex]So, the temperature when the plane climbs 30000ft is of -37°.
