Question

which unit of measure is the correct si unit to use in measuring the mass of a boulder?
○ pounds
○ ounces
○ kilograms
○ tons

Explanation:

1. Recall the definition of SI units (International System of Units) for mass. The base SI unit for mass is the kilogram.
2. Analyze each option:

• Pounds and ounces are units of weight (force) in the imperial system, not SI units for mass.
• Tons (e.g., metric ton is 1000 kilograms, but "tons" can also refer to imperial tons) is not the base SI unit for mass.
• Kilograms is the base SI unit for mass, suitable for measuring the mass of a boulder (as boulders have significant mass, and kilograms are appropriate for such measurements within the SI system).

Answer:

C. kilograms