I want to design objects with specific mass, how it is possible?
Change your material, thats it to go
Are you looking to retroactively assign a mass to a part? You can fudge it in the BOM for quick and dirty. I noticed you haven't assigned a material to the part you have attached. In that regard, you could assign any number of materials of varying densities to your part. Aluminium will have a total mass less than that of stainless which is less than that of uranium, etc.Are you shooting for something more exotic? You can add custom materials to the SW database if they aren't in there. Perhaps someone has a more extensive database?
Thank you..I will check it...
You can also go to document properties and set the density in Material Properties (but that is old school, setting material is the way to go).
if you dont want to change the dimensions you can use it
if you have to change the dimensions, you have to make a Sensor and Parametric design,