"board eraser" is "(der) Schwamm" ("sponge") or "(der) Tafelschwamm" ("(black)board sponge") in German.
eraser - Radiergummi
eraser [I'reize] n Radiergummi m
eraser = Radiergummi
Goma de borrar, borrador.
Tafelwischer
Tafelreiniger
The purpose of a Chalkboard Eraser is to wipe off, or "erase," anything that is written on a Chalkboard. Things are usually written on Chalkboards using Chalk, and an eraser lifts the layer of chalk of the chalkboard, leaving it free again.
how much does chalkboard eraser weigh in grams
die Tafel
245.8
Chalkboard erasers come in a number of different sizes, so, clearly it depends on the particular eraser. An eraser 5" x 2" x 1.5" in not uncommon. Its volume would be 15 cubic inches.
The likely word is "eraser" (e.g. for a chalkboard or pencil writing).
un effaceur (du tableau noir)
the average is 150 cubic centimeters
They hit at the same time.
chalkboard desks floor eraser
they would hit at the same time
Chalkboard erasers are made of felt. Felt is hair. Hair does not conduct electricity. Felt has lots of air entrained between the hair fibers so, it conducts heat poorly, too.