Weight
The downward gravitational force exerted on an object's mass by a surrounding gravitational field.
Governing formula
W = m g
SI unit
N
In depth
Unlike intrinsic mass, weight is a location-dependent vector force. Weight changes depending on local gravitational field strength g (e.g., on different planets or altitudes).
Examples in the real world
An 80 kg astronaut weighs ~784 N on Earth (g = 9.8 m/s²), but only ~130 N on the Moon (g = 1.62 m/s²).