Distinguish between mass density and weight density?
The difference is that the mass density not effect by gravity
but weight density effect by gravity. for example if mass density
cotn in earth equal to 20 kg/m3 and weight density equal to 196.2
N/m3 this cotn will change the weight density in the moon but mass
density not change because gravity moon diffrent to gravity
earth
mass density =mass/volume (no gravity)
weight density= (mass * gravity)/volume (gravity)