Question

why we measure weight in kg and why not in newton

Answer 1

Yes. When we use kilograms to measure weight, we are actually referring to k g f or kilogram-force......
And as we know that  weight(force) of one kg is equal to one kgf, or 9.8N.........

>>Newton is the SI unit of Force and We know that Force is equal to the product of Mass and Acceleration.......
and Kg is the SI unit of Mass _______________________

Answer 2

we can measure weight in newton because the SI unit of weight is newton...