# The Answer Is Not 0

Consider air at sea level on the surface of the earth at $$20^o~C$$, pressure $$p_0$$ (in Pascals) and a mass density $$\rho_0$$. Let the pressure 10 m above sea level be $$p_{10}$$. Let the pressure 20 m above sea level be $$p_{20}$$. What is

$$\frac{p_0-p_{20}}{p_0-p_{10}}-2$$?

You may consider air to be entirely nitrogen for the purposes of this problem.
The acceleration of gravity is $$-9.8~m/s^2$$.

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