when I read what inertial frames I understand and it make sense but unfortunately when I try to apply what I understood on that question ,I cant illustrate these frames. Please help. question is that: I am standing on a level floor at the origine of an inertial frame ( S) and kick a frictionles puck due north across the floor. a) write down x and y coordinates of the puck as functions of time as seen from my inertial frame . (if I take x and y axes pointing east and north) than I can say that since the net forces on the puck is 0 , the puck will have a constant velosity toward north. ( x,Y ) = ( 0, vot) b) now consider more observers,the first at rest in a frame (S')that travels constant velocity v due east relative to (S),the second at rest in a frame (S'') that travels with constant acceleration due east relative to (S). Find the ( x`,y`) of the puck and describe the puck`s path as seen from (S'). c) do the same for (S'') which of the frames is inertial ? ( which I know if the frame is accelerating then it is not inertial) ( I think I solved the problem just after I wrote here. ) thanks How can I do that ? Is thare any resources you know that I can read and maybe see some similar examples ?