A railway carriage of mass 60 tonnes moving south at 4.50m/s rams into another carriage of a mass if 85 tonnes which is also moving. On colliding they lock and move together southward at 2.50 m/s. At what speed and directions was the heavier carriage moving before they collided?
(if you can explain the process that would be helpful)
(if you can explain the process that would be helpful)