CAN SOMEONE HELP ME PLZ

Ryan is examining the energy of the particles in a bar of gold. what is ryan most likely studying?

Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. after chatting for a few minutes, she walks 125 meters to the west to meet a friend and then walks 45 meters north with her friend to a cafe for lunch. overall, she takes 10 minutes to do all this. what is mary’s average speed?

Aruby has a density of 3.9 g/cm³. what is the mass of the ruby, if its volume is 5 cm³? a. 0.78 g b. 1.28 g c. 8.9 g d. 19.5 g