If p(Density) is constant,what happens to V(Velocity) if M(Mass) increases?

Answer 1

According to relativistic theory, the mass which a body has when it is at absolute rest. Mass increases when the body is in motion according to
where m is its mass in motion; m0 is its rest mass; v is the body's speed of motion; and c is the speed of light.
Newtonian physics, in contrast with relativistic physics, makes no distinction between rest mass and mass in general.

Answer 2

Density cannot be constant if mass increases.