4 s A- 2: here Unit A - 1: List of Subjects

• A substance of 15 pounds mass “weighs” 15 pounds force. • A substance of 85 kilogram mass “weighs” 85 kilogram force. Problems: • Pound mass (lbm) is “inconsistent” mass unit, and cannot be used against pound force (lb). • Kilogram force (kgf) is “inconsistent” unit, and cannot be used against kilogram mass (kg). ................
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