Question

What is the value of g

Answer 1

It depends on the environment around you ... the number and size of
the masses around you, and your distance from their center of mass.

If you happen to be on the surface of the Earth, then

                       g  =  9.8 m/s²
       or
                       g  =  9.8 newton/kilogram .

It's different on other planets.  Be sure to look it up
before you leave, so you'll know what to expect.