Statement I: The acceleration due to gravity decreases with increase in height from the surface of the Earth. Statement I : The acceleration due to gravity is inversely proportional to the square of the distance from the centre of the Earth.

Statement I is true because the acceleration due to gravity (g) decreases as altitude increases above the Earth's surface. This occurs because a greater altitude results in a greater distance from the Earth's center. Statement II is also true and provides the physical basis for Statement I. According to Newton's law of universal gravitation, the gravitational force and the resulting acceleration are inversely proportional to the square of the distance (r) from the center of the Earth, expressed as g ∝ 1/r². As an object moves further from the center (increasing height), the denominator in this inverse square relationship increases, causing the value of g to decrease. Therefore, Statement II correctly explains why gravity weakens with height.

Sources

1. [1] https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/weight-equation-2/
2. [2] https://en.wikipedia.org/wiki/Gravity_of_Earth