$A$ body of mass $10 \,kg$ is taken to the centre of the earth. What will be its mass there (in $,kg$)?

You find your mass to be $42\, kg$ on a weighing machine. Is your mass more or less than $42\, kg$?

If your weight on the Earth is $450 N$,calculate your weight on planet Mars. (Radius of Mars $= 4.3 \times 10^{6} m$,mass of Mars $= 6 \times 10^{23} kg$ and gravitational constant $G = 6.67 \times 10^{-11} Nm^{2} kg^{-2}$). Take acceleration due to gravity on Earth as $10 m s^{-2}$.

It is said that the mass of an object remains constant at all places,while its weight may change. Why?

How does the weight of an object vary with respect to the mass and radius of the Earth? In a hypothetical case,if the diameter of the Earth becomes half of its present value and its mass becomes four times its present value,then how would the weight of any object on the surface of the Earth be affected?

Why is the weight of an object on the moon $\frac{1}{6}^{th}$ its weight on the Earth?