70F05 Two-body problems
70F07 Three-body problems
70F10 $n$-body problems
70F15 Celestial mechanics
70F16 Collisions in celestial mechanics, regularization
70F17 Inverse problems
70F20 Holonomic systems
70F25 Nonholonomic systems
70F35 Collision of rigid or pseudo-rigid bodies
70F40 Problems with friction
70F45 Infinite particle systems
70F99 None of the above, but in this section