Final answer:
In Physics, specifically mechanics and engineering, bodies in the U.S. customary system are characterized by their weight in pounds rather than their mass in slugs due to the relatively constant gravity on earth.
Step-by-step explanation:
In the U.S. customary system of units, bodies are typically characterized by their weight in pounds instead of their mass in slugs when studying Physics, particularly in the fields of mechanics and engineering. Weight is a measure of the force exerted on a body due to gravity, while mass is a measure of the amount of matter in the body. However, because the acceleration due to gravity is relatively constant on the earth's surface, we can often use the 'weight' in everyday language instead of 'mass', because the ratio or relationship is known. Fundamentally, in studies and calculations, the distinction is important to understand the differing behaviors of objects under varying gravitational environments.
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