Understanding Weight and Mass

* Mass is the amount of matter in an object. It's a fundamental property and is measured in kilograms (kg).

* Weight is the force of gravity acting on an object's mass. It's measured in Newtons (N).

The Formula

Weight (W) = Mass (m) × Acceleration due to gravity (g)

* g is approximately 9.81 m/s² on Earth's surface.

Calculation

W = 90 kg × 9.81 m/s²

W = 882.9 N

Answer: The weight of a 90 kg mass is approximately 882.9 Newtons.