Question

SI unit of gravitational constant is:
(A). $N^{2}m^{2}kg^{2}$
(B). $N m kg^{2}$
(C). $N^{2}m kg^{-2}$
(D). $Nm^{2}kg^{-2}$

Answer 1

Hint: The SI system of unit measurement is the international system of measurement of units. The SI unit of the measurement is accepted world-wide. The SI system is formed to make the communication easy world-wide.

Complete step-by-step answer:

The gravitational force of attraction between any two objects is:
Directly proportional to the product of masses
Inversely proportional to the square of distance between them.
The gravitational force of attraction is given by,
$F=\dfrac{Gm_{1}m_{2}}{r^{2}}$
Where, G is the gravitational constant, $m_{1}m_{2}$are the masses of the objects and r is the distance between the objects
So, the gravitational constant is given by,
$G=\dfrac{Fr^{2}}{m_{1}m_{2}}$
In SI system:
The unit of force is Newton and it is written as, N. The unit of distance is meter and it is represented by m. The unit of mass is kilogram and it is represented by kg.
$G=\dfrac{Nm^{2}}{kg \times kg}$
$G= Nm^{2}kg^{-2}$
Thus, the correct option is D.

Note: The value of the gravitational constant is the universal constant. For different parts of the universe the value of the gravitational constant remains the same.