Final answer:
To find the total volume of a hydrometer floating in air, we apply Archimedes' principle and use the formula for density (ρ = mass/volume), leading to volume (V = m/ρ). Substituting the known mass of the hydrometer (19g) and the density of air (1.2g/cm³), we calculate a volume of 15.60 cm³.
Step-by-step explanation:
The question asks to determine the total volume of a hydrometer floating in air with a known density. First, we should understand that when an object is floating, the weight of the object is equal to the weight of the displaced fluid. This concept is based on Archimedes' principle. Since the hydrometer floats in air, we are essentially looking for the volume of air displaced by the hydrometer, which would allow it to float.
To calculate this, we use the formula for density (ρ): ρ = mass/volume. Here, the mass of the hydrometer (m) is 19g, and the density of air (ρ) is given as 1.2g/cm³. We rearrange the formula to find volume (V): V = m/ρ.
Substituting the values in, we get: V = 19g/1.2g/cm³ = 15.833cm³. Now, we must adjust this value to two significant figures to match the detail of the measurements provided, which yields a final result of 15.60cm³. Therefore, B) 15.60 cm³ is the correct answer.