How do i differentiate b/t an action/reaction force described in Newton's Third Law acting on two different bodies, with the normal force and the weight force acting on the same body. eg: Scenario 1: a bin rest on a table: the weight force of the bin exerts on the table due to gravity, and the normal force provided by the table acting on the bin. (Both arrows representing the force are shown on the bin). Thus the bin is stationary. Scenario 2: Similar to scenario 1 but this time the normal foce arrow is shown on the bin and the force bin exerts on table is shown on the table. And this is the action/ reaction force described by Newton. Not like the first scenario. Very confussing! How do i know when the force is on the same body or on different bodies. B/c both scenarios are similar. Any suggestions???