Question

A bar of metal has a mass of 200 g and has a certain weight at the poles. Mass remains the same but weight decreases when weighed at the equator. Why?

Answer 1

1. The mass of an object is defined as the quantity of matter contained in it.
2. It is the measure of its inertia, which is a scalar quantity that remains the same irrespective of the position of the object.
3. Hence, as mentioned in the question, the mass of the bar of the metal remains constant.
4. The weight of an object is the magnitude of the force with which it gets attracted by the earth.
5. The weight of an object (W) is defined as the product of the mass of the object and the acceleration due to gravity (g). i.e., W = mg.
6. So, the weight of an object depends upon the acceleration due to gravity (g).
7. As the value of g decreases when we move from the poles to the equator, the weight of an object also decreases accordingly.
8. This is the reason why the weight of the bar of the metal decreases when we move from the poles to the equator.