Question

What is valocity and dencity?​

Answer 1

ρ = density, V = velocity, A = flow area. Mass Flow Rate is defined as the transfer of a mass of substance per unit of time. Mass flow rate can be calculated from the density of the liquid (or gas), its velocity, and the cross sectional area of flow.

Answer 2

velocity is the speed of an object in a given direction

so if the speed was 4 m/s to the right, the velocity to the right would be 4m/s

however the velocity to the left would be -4m/s

density is the amount of matter an object has in a given space

it can be calculated as

density = mass / volume