Stowaway

Temperature in degrees Celsius (horizontal scale) versus Altitude if thousands of feet (vertical scale)

Tam talks about airliner stowaways and links to a gummint PDF wherein they mention a rule of thumb for calculating the temperature at a given altitude, so I thought I would plot it to see if it checked out.

The rule is given in this paragraph:

'double the first two numbers of altitude' is the same as dividing by 1,000 and the multiplying by 2, which is the same as dividing by 500. In order to make the graph readable, we are going to scale the altitude by a factor of 1,000, so we can leave off with the dividing by 1,000. Munging it around we end up with an equation that looks like this:

The section at the end tells Desmos that we don't care about altitudes (y) below ground level or above 40,000 feet.

I should compare this equation with another source, but duty calls, so no.