What is the magnitude of the net force ∑ F on a 1.9 kg bathroom scale when a 74 kg person stands on it?

725.2‬ N

Explanation:

Since it is not stated the scale, the person or both accelerated or experience weightlessness, the net force acting on the bathroom scale is the weight of the person acting downward as the person stands on the scale.

Weight = mass of a body * acceleration due to gravity

= 74 kg * 9.8 m/s²

= 725.2‬ N