Question

The force of gravity cannot act at a distance. Is this statement true or false?
A. True
B. False

Answer 1

Hint: The gravitational force is given by the equation
$F = G\dfrac{{{m_1}{m_2}}}{{{r^2}}}$
Where ${m_1}$ and ${m_2}$ are the mass of objects, $G$ is the gravitational constant having value $G = 6.7 \times {10^{ - 11}}\,N{m^2}k{g^{ - 2}}$., $r$ is the distance between the two objects

Complete step by step answer:
According to Newton's law of gravitation, every object in the universe attracts every other object with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between the two masses.
Mathematically it is written as
$F = G\dfrac{{{m_1}{m_2}}}{{{r^2}}}$
Where ${m_1}$and ${m_2}$are the mass of objects, $G$ is the gravitational constant having value $G = 6.7 \times {10^{ - 11}}\,N{m^2}k{g^{ - 2}}$, $r$ is the distance between the two objects
From this equation it is clear that gravitational force is inversely proportional to the square of distance. Which means that the effect of force decreases as distance increases.
Hence given statement is false
So, the answer is option B.

Additional Information: From the expression for universal law of gravitation it is clear that as we move higher from the earth surface the gravity decreases. Because as the height increases the distance between earth and the object increases so force decreases since gravitational force is inversely proportional to square of distance.
But if we go deeper inside of the earth the gravity decreases instead of increasing. This happens because the mass that exerts gravitational pull on us becomes less. Suppose we are at a radius $r$ in side the earth surface which is less than the actual radius of earth. Then only the mass which is below us exerts gravitational pull. The mass above our level will not exert any pull. So as we go deeper and deeper the mass below becomes less. So the force of gravity will decrease.


Note: Gravitational force is the weakest of all four fundamental forces. Though the strength of gravitational force decreases with distance, its range is infinity. The value will decrease considerably with increasing distance but it is still present everywhere. For example there is a gravitational pull acting on us due to the sun but we are not aware of it since its value is so small.