Final answer:
The mass of the marble is 0.002 kg, and it remains the same as the question asks for an approximate mass in the same unit (kilograms). Precision is important in such measurements, and the given mass is already precise to three significant figures. No unit conversion is needed in this answer.
Step-by-step explanation:
The student's question about the mass of a marble that has a mass of 0.002 kg, is seeking its approximate mass in kilograms. Since the mass is already given in kilograms, its approximate mass remains the same, 0.002 kg. It is important to note that when dealing with measurements, precision and significant figures play a crucial role. In this case, the mass is already expressed to three significant figures, which is quite precise for such a small mass.
The standard unit of mass in the SI system is the kilogram (kg). One kilogram is about 2.2 pounds. Conversion between units is commonly required in physics problems. However, since this question begins with the mass in kilograms, no conversion is necessary. If we were to express the mass in grams, which is 1/1000th of a kilogram, this marble would weigh 2 grams (0.002 kg = 2 grams).