Question

methodology of knowing the weight of the object on different planet​

Answer 1

We calculate weight by multiplying mass by the gravity on the surface of the planet. So, if you know your weight on Earth and the surface gravity on Earth, you can calculate your mass. You can then calculate your weight on any other planet by using the surface gravity of that planet in the same equation.

Answer 2

We calculate weight by multiplying mass by the gravity on the surface of the planet. So, if you know your weight on Earth and the surface gravity on Earth, you can calculate your mass. You can then calculate your weight on any other planet by using the surface gravity of that planet in the same equation.