Question

4. Is the constant density assumption appropriate when describing the behaviour of air at the top
of Mt. Logan in Yukon Territory, Canada (elevation = 5,959 m)? (1 mark)

Answer 1

No.

Since a gas is compressible, its density depends on the force that is used to compress it.

At the surface, the force that compresses the air is the weight of all the air in the atmospheric column above it.

The higher we go in the atmosphere, the less air remains in the column above us. Thus the atmospheric pressure always decreases with height. Similarly, air density decreases with height because the overload to compress the air gets less and less, as we go higher.