Question

The force of attraction between two unit point masses separated by a unit distance is called
A) Gravitational potential
B) Acceleration due to gravity
C) Gravitational field
D) Universal gravitational constant

Answer 1

Hint: The force of attraction between two bodies depends on the mass of the bodies and the distance separated. It obeys the inverse square law. The proportionality constant is known as the Universal gravitational constant.

Formula used:
The force of attraction between two bodies of mass ${m_1}$ and ${m_2}$ separated at a distance $r$ is given as,
$F = G\dfrac{{{m_1}{m_2}}}{{{r^2}}}$
Where, G is the universal gravitational constant.

Complete step by step solution:
The force of attraction between two bodies of mass ${m_1}$ and ${m_2}$ separated at a distance $r$ is given as,
$F = G\dfrac{{{m_1}{m_2}}}{{{r^2}}}$
Where, G is the universal gravitational constant.
When the masses are two unit point masses and they are separated by a unit distance, then the force of attraction is given as
$F = G\dfrac{{1 \times 1}}{{{1^2}}} = G$
The force of attraction is the universal gravitational constant.

Therefore, option D is the correct answer.

Additional information:
- In the universe, every body will attract each other. And this force is proportional to the product of the masses of the particle and the distance between them.
- The direction of the force is along the line of joining two particles. The Coulomb’s law in the electrostatics resembles Newton's law of gravitation hence they are forced between two charges.
- Both are inverse square laws. Newton proves this law that the same force which causes the apple to fall to the ground is also responsible for the moon to orbit around the earth.

Note:
The Universal gravitational constant is directly related to the magnitude of the mass of two bodies and the distance between them. If the mass of the bodies are point mass and if they are separated at a distance of one unit then the force of attraction will be the gravitational constant. And the value of Gravitational constant is $G = 6.67 \times {10^{ - 11}}\;{\text{N}}\;{{\text{m}}^{\text{2}}}\;{\text{K}}{{\text{g}}^{{\text{ - 2}}}}$