Hello

Is there an engineering term that references a body of material’s resistance to penetration?

Interested in the body being fluid (water) as well as semi sold (i.e. granular cereal foods).

One case in point: I am attempting to configure a weight that will penetrate water but will stop at the layer of settled silt. The goal is to gauge the height of the silt level. If I can qualitatively measure the silt's resistance to penetration by a given object I hope to apply this to several different settled solids.

Have other application by where we will be attempting to gather similar quantitative information on an object passing though a semi solid material (i.e. an agitator blade through dry granular cereal foods)

Thank you