Question

The acceleration due to gravity at three places $\text{A},\text{B},$ and $\text{C}$ on Earth are given by $9.8\text{m}{\text{s}}^{-2},9.81\text{m}{\text{s}}^{-2}$ and $9.78\text{m}{\text{s}}^{-2}$ respectively. Which of the following statements is true?

• A. $\text{B}$ is the nearer to the centre of the Earth than the other two.
• B. All of the above.
• C. The order of the strength of the Earth's gravity is $\text{B}>\text{A}>\text{C}$.
• D. $\text{C}$ is the farther from the centre of the Earth than the other two.

Answer 1

The correct option is B All of the above.

Acceleration due to gravity: $\text{g}\propto \frac{1}{{\text{R}}^2}$
where $\text{R}$ is the distance from the center of the Earth which is variable in nature.

Out of the three given points, $\text{C}$ has the least $\text{g}$, and hence, it is farther from the centre of the Earth than the other two. Similarly, $\text{B}$ has the greatest $\text{g}$, and hence, it is nearer to the centre of the Earth.
For an object of mass $\text{m}$, it experiences a gravitation pull of $\text{mg}$, so, the order of the strength of the Earth's gravity the object experiences, is $\text{B}>\text{A}>\text{C}$.