Which statement correctly differentiates mass and weight in SI units?

Which statement correctly differentiates mass and weight in SI units?

• A. Mass is a force measured in Newtons; Weight is mass in kilograms.
• B. Mass is the amount of matter measured in grams; Weight is in kilograms too.
• C. Mass is the amount of matter measured in kilograms; Weight is the force of gravity measured in Newtons.
• D. Mass is in meters; Weight is in newtons.

Answer: (C)

In SI units, mass and weight are two different quantities: mass is the amount of matter and is measured in kilograms, while weight is the gravitational force acting on that mass and is measured in newtons. The relationship between them is F = m g, so weight depends on gravity and has units of force (newtons) because 1 newton equals 1 kilogram meter per second squared. That’s why the statement that mass is the amount of matter measured in kilograms and weight is the force of gravity measured in newtons is the right differentiation. The other options mix up the concepts: mass isn’t a force in newtons, nor is weight measured in kilograms; and mass isn’t measured in meters.

In SI units, mass and weight are two different quantities: mass is the amount of matter and is measured in kilograms, while weight is the gravitational force acting on that mass and is measured in newtons. The relationship between them is F = m g, so weight depends on gravity and has units of force (newtons) because 1 newton equals 1 kilogram meter per second squared.

That’s why the statement that mass is the amount of matter measured in kilograms and weight is the force of gravity measured in newtons is the right differentiation. The other options mix up the concepts: mass isn’t a force in newtons, nor is weight measured in kilograms; and mass isn’t measured in meters.