Two astronauts are floating in gravitational free space after having lost contact with their spaceship. The two will:

Two identical particles each of mass $m$ go round a circle of radius $a$ under the action of their mutual gravitational attraction. The angular speed of each particle will be

The force of gravitation is:

Two objects,each of mass $1\,kg$,are placed at a distance of $10\,cm$ from each other. Calculate the gravitational force between them.

The change in the value of acceleration of the earth towards the sun,when the moon moves from the position of a solar eclipse to the position on the other side of the earth in line with the sun,is: (mass of the moon $= 7.36 \times 10^{22} \ kg$,radius of the moon's orbit $= 3.8 \times 10^8 \ m$).

The $SI$ unit of $\frac{G}{g}$ is $(g = \text{acceleration due to gravity}, G = \text{gravitational constant})$