Answer;
-Gases
Explanation;
-Pressure can affect the density of gases.
-Density of gases changes with pressure and temperature because gases are compressible fluid and because they are compressible, when pressure increases molecules come closer to each other which means increase in density and when pressure drops molecules of gases become free to expand and get away from each other which density decrease.
It describes the relationship between force and acceleration
I would say mass, and weight.
When It begins to drop because that when gravity will have its strongest pull on the object.
