Question

The mass of a body:
A. Is slightly different at different places on earth.
B. Is independent of the froe-fall acceleration.
C. Is the same for all bodies of the same volume.
D. Can be measured most accurately on a spring scale.

Answer 1

Hint: A body's mass is its inertia or resistance to motion-change. More precisely, under the influence of a given force, it is a property of the body that determines the acceleration of the body. A body's mass is the quality of its substance and is independent of its position, acceleration and free fall.

Complete solution:
We know a body's mass is its inertia or resistance to motion change. When some force is applied, we can say mass is both a property of the physical body and a measure of its resistance to acceleration. We can now say that a body's mass is the quality of its matter and is independent of its location, its acceleration, and the acceleration of free fall. Wherever we go, as we know, the mass of our bodies never changes.

Mass of any body is given by $m=\rho \times v,$ where $\rho$ is the density of the body and $v$ is the volume.

So, we understand that if density varies, then mass will be different for the same volume. Because it measures the weight of a body that is different at different locations, it can not be measured by spring balance.

So, if we see the option above the option B could be the best possible answer, as the mass of a body is independent of the acceleration of free fall. And as the mass remains the same at every location on earth, the rest of the alternatives are not correct. Also for all bodies of the same volume, if the density changes, the mass will not be the same. And the last option is also wrong, as the weight is not the mass measured by the spring scale.

So, we can only see, the option 'B' is correct, but the other options are incorrect.

Note:
Whenever such kinds of questions arise, try to know what mass actually means first. A body's mass is its inertia, as stated in the solution. And then check each option to see whether or not they are correct.