Hi this is my id what is physics​

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

The midpoints? a, b, and c are marked on the histogram. match them to the indicated scores. which? scores, if? any, would be considered? unusual?

What type of nuclear decay causes the atomic number of an element to increase by 1?