Question

why is the weight of the same object different on different plants​

Answer 1

The weight of the same object on another planets may vary bacause of gravity

Answer 2

Answer:

Because W = mg and it varies with the value of 'g'

and g varies with planet to planet for example value of g for moon is 1.6 m/s²

and for earth is 9.8 m/s².

more example

suppose a man of 90 kg has weight of 882 N  on the Earth  whileits weight on the moon reduces to 144 N.