When the liquid is completely immersed, a buoyant force acts on a body with a volume of 8 dm3, which is 78.4 N, what kind of liquid it is.

Data: V (the volume of a body completely immersed in the liquid under study) = 8 dm3 (in the SI system V = 8 * 10-3 m3); Fa (buoyancy) = 78.4 N.
Constants: g (acceleration due to gravity) = 9.8 m / s2.
To find the type of liquid under investigation, we apply the formula: Fa = ρх * g * V and ρх = Fa / (g * V).
Calculation: ρх = 78.4 / (9.8 * 8 * 10-3) = 1000 kg / m3.
Answer: The body was immersed in fresh water.