Understanding the Concepts

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

* Mass: Mass is the amount of matter in an object. It's measured in kilograms (kg).

* Acceleration due to Gravity (g): On Earth, the acceleration due to gravity is approximately 9.8 m/s².

Formula

The relationship between weight, mass, and acceleration due to gravity is:

Weight (W) = Mass (m) * Acceleration due to Gravity (g)

Solving for Mass

1. Rearrange the formula: m = W / g

2. Plug in the values: m = 3920 N / 9.8 m/s²

3. Calculate: m = 400 kg

Therefore, the mass of the piano is 400 kg.