a)
Volumen großer Kegel: Vg = 1/3 · (1,4dm)^2·π/4 · 6,125dm
Volumen kleiner Kegel: Vk = 1/3 · (1dm)^2·π/4 · 4,375dm
V = Vg - Vk = 1/3 · (1,4dm)^2·π/4 · 6,125dm - 1/3 · (1dm)^2·π/4 · 4,375dm = π/12·((1,4dm)^2·6,125dm - (1dm)^2·4,375dm)
m = ρ·V
m = 8,6kg/dm^3 · π/12·((1,4dm)^2·6,125dm - (1dm)^2·4,375dm)
m ≈ 17,18kg
m = ρ·V = 8,6kg/dm^3 · 2dm^3 = 17,2kg
b) F=m·g
Beste Grüße
gorgar