2 4 5 6 6 7 RE TIME REI 47: an object of the same mass has three different weights at different times. Which statement is possible? ​

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Which is the most accurate name for the covalent compound p2o3?

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?