Determine what a spring balance will show if an iron body with a volume of 100 cm3 is weighed in kerosene?

To find out the required indication of the spring balance, consider the formula: P = Ft – FA = mt * g – ρk * g * Vt = ρl * Vt * g – ρk * g * Vt = Vt * g * (ρl – ρk).

Const: q – free fall acceleration (approx. Q ≈ 10 m / s2); ρzh is the density of iron (ρzh = 7874 kg / m3); ρк – density of kerosene (ρк = 805 kg / m3 (KO-25)).

Data: Vt is the volume of an iron body (Vt = 100 cm3 = 10 ^ -4 m3).

Let’s make the calculation: P = Vt * g * (ρzh – ρk) = 10 ^ -4 * 10 * (7874 – 805) = 7.069 N ≈ 7.1 N.

Answer: The spring balance should show that the body weight of iron is 7.1 N.