The area of that cross section is the well known A = pi*R² which is colloquially pronounced as “pie are squared.” We will put aside the old joke that “Pie are not squared; pie are round” but we have ...

In physics, a cross section describes the likelihood of two particles interacting under certain conditions. Those conditions include, for example, the number of particles in the beam, the angle at ...

If you assume the density of air is 1.2 kg/m 3, what is the drag coefficient C for a coffee filter? You will need to find the cross sectional area of a filter. You can use the picture above.