Question

If the gravitational force of earth suddenly disappears, then which of the following is correct?
(A) Weight of the body is zero
(B) Mass of the body is zero
(C) Both weight and mass become zero
(D) Neither the weight nor the mass is zero

Answer 1

Hint To find the correct option, you first need to know the basic conceptual difference between mass and weight of a body. Also, check whether the mass is dependent on the acceleration due to gravity or not, and whether the weight depends or not.

Complete step by step answer:
As explained in the hint section of the solution to the question, to solve the question, we first need to know the basic conceptual difference between the weight and mass of a body and which of the two actually depends on the acceleration due to gravity and which one is independent of the acceleration due to gravity of earth. For that, let us first explain the term mass:
Mass is a quantitative measure of inertia and the most fundamental property of all matter. In other words, it is the resistance that a body of matter offers to a change in its speed or position upon the application of a force. The greater the mass of a body, the smaller the change produced by an applied force.
Now that we have defined mass, we can see that there is no mention of acceleration due to gravity and no sign that mass is dependent on acceleration rather, mass is a property that opposes the change in the motion of the body. Hence, even if the gravitational force on earth disappears, there will be no effect on the mass of the body. This completely discards the option (B) and option (C) as the correct answer since mass will not be zero even if the gravitational force on earth disappears.
Now let us have a look at the term weight of a body:
Weight can be defined as the force exerted on a body due to the gravitational pull or gravitational force or field on a body. Since weight is a force, it needs a pull or acceleration to exist and has a unit of N (newton). If the gravitational force on earth disappears, then there would be no acceleration acting on a body downwards, hence, there will be no force acting on the body due to gravity, hence, the weight of the body will become zero.

Hence, we can see that the correct option as the answer to the question is option (A).

Note Many students assume that there is no factor which can change the value of both mass and weight and think of them as almost the same thing because of the crude use of both the terms in normal day life, which gives them the wrong notion that both the mass and weight of a body are the same thing.