In problem 3 of chapter 2 of Landau Lifshitz "Mechanics," I don't understand the meaning of the fields as defined in the following statement:
Which components of momentum and angular momentum are conserved in motion in the following fields?
(a) the field of an infinite homogeneous plane,
(b) that of an infinite homogeneous cylinder,
(c) that of an infinite homogeneous prism,
(d) that of two points
I just don't get what he's trying to say. Does he mean an electric field produced by a uniformly charged infinite plane, or an uniformly charged cylinder, etc.?