Plz i need help please help

A6,600 kg train car moving at +2.0 m/s bumps into and locks together with one of mass 5,400kg moving at -3.0m/s. what is their final velocity? +0.50 m/s -1.0 m/s +2.5 m/s -0.25 m/s

How many times did thomas edison mess up the light bulb

If a stone with an original velocity of 0 is falling from a ledgeand takes 8 seconds to hoybthe ground whays the final velocity of the stone