# Projectile Type

Selecting a **Projectile** from the drop down list of projectiles will automatically
fill out the Mass of Projectile and
Projectile Diameter inputs. If
the projectile you are using is not on the list, choose the custom option.

The baseball and golf ball options are special cases. They each have their own curve for calculating the drag coefficient. For all the other options, the simulation uses the smooth sphere curve for calculating the drag coefficient. For more information about calculating the drag coefficient see the Projectile Drag section.