Is there a force of friction between the wheels of a moving train and iron rails? If yes, name the type of friction. If an air cushion can be introduced between the wheel and the rail, what effect will it have on the friction?
Yes, the force of friction is rolling friction when the train is moving, when the brakes are applied kinectic friction acts and when the train is static(rest position) the friction acting on it is static friction.
If an air cushion is inserted then the force of friction will be zero due to the rail and the wheels bcz we know that friction is a contact force and if air is introduced there will not be any contact. This is what actually happens in a MAGLEV TRAIN it makes use of electromagnetism to keep the train lifted a few millimetres (15) which helps them to achieve extraordinary speeds.
If an air cushion is inserted then the force of friction will be zero due to the rail and the wheels bcz we know that friction is a contact force and if air is introduced there will not be any contact. This is what actually happens in a MAGLEV TRAIN it makes use of electromagnetism to keep the train lifted a few millimetres (15) which helps them to achieve extraordinary speeds.