Which SI unit is used to measure the mass of an object?

• A. kilogram
• B. second
• C. meter
• D. liter

Answer: (A)

Verified step by step guidance

1. Understand that the problem asks for the SI unit used to measure the mass of an object.
2. Recall that the International System of Units (SI) defines specific base units for different physical quantities: for example, meter (m) for length, second (s) for time, kilogram (kg) for mass, and liter (L) for volume.
3. Identify that mass is the amount of matter in an object, and its SI base unit is the kilogram, symbolized as \(\text{kg}\).
4. Note that the other options correspond to different physical quantities: second (\(\text{s}\)) measures time, meter (\(\text{m}\)) measures length, and liter (\(\text{L}\)) measures volume, which is not an SI base unit but a common unit for liquids.
5. Conclude that the correct SI unit for mass is the kilogram (\(\text{kg}\)).