Question

_________ of a body changes from place to place but its _______ remains constant.
A. Weight, mass
B. Mass, weight
C. Mass, force
D. Mass, gravity

Answer 1

Hint: As a first step you could recall the definition of mass. In doing so, you may realize that the mass of the body doesn’t change by changing its location. From this point you could understand that some of the options aren’t right at the first glance. Also, you could recall the definition of weight to make sure that your answer is right.

Complete answer:
Before answering the given question, let us understand the difference between mass and weight. Mass of an object is actually the measure of the object’s inertial property or we could also define it as the amount of matter an object contains whereas, weight of an object is the measure of the gravitational force exerted on the object or the force that is required to support it.
Now that you know the definition of both the quantities, you know that the amount of matter contained within an object doesn’t change when you take that object from place to place or even to the other corner of the universe. However, the gravitational force on an object does vary from place to face. The weight of the body is actually given by the product of mass with acceleration due to gravity.
The value of acceleration due gravity of earth is very different from moon, even its value varies with height and depth within earth.
So, we could conclude that, mass of a body doesn’t change from place to place but weight does.

$\therefore $ Weight of a body changes from place to place but its mass remains constant. So, the correct answer is “Option A”.

Note: In our daily life we often use weight as a synonym for mass. But as a physicist you should understand that the terms ‘net mass’ and ‘net weight’ on a label just specifies the amount of that particular commodity contained within the packet. Also, the SI unit of mass is kilogram and that of weight is Newton.