Question

A 500g metal ball is brought to the moon. What is its weight on Earth? on the moon? What is its mass on Earth? on the moon?

Answer 1

1. The weight is given as follows:

$$W = mg$$

where $m = 0.5kg$ is the mass of the ball, $g$ is the gravitational acceleration. On Earth: $g\approx 9.8m/s^2$, on Moon: $g\approx 1.6m/s^2$.

Thus, obtain weight on Earth:

$$W_E = 0.5kg\cdot 9.8m/s^2 = 4.9N$$

On Moon:

$$W_M = 0.5kg\cdot 1.6m/s^2 = 0.8N$$

2. The mass is always the same regardless of the planet.

Answer. Weight on Earth: 4.9N, weight on Moon: 0.8N, mass on Earth: 0.5kg, mass on Moon: 0.5kg.