An apple falls because of the gravitational attraction of earth. What is the gravitational attraction of apple on the earth?

Two masses of $‘m’$ each are suspended side by side at distance $‘a’$, by two equal threads of length $‘b’$ If ’ is the angle that threads make with vertical due to attraction between masses, then $\alpha$ is :

If an angel visits an asteroid called $\mathrm{B} 612$ which has a radius of $20 \mathrm{m}$ and mass of $104 \mathrm{kg}$, what will be the acceleration due to gravity in $\mathrm{B} 612$ ?

The force between a hollow sphere of mass $M$and a point mass $‘m’$at P inside it (Shown in figure): ($PC=X$, Radius $=r$) 

What is the relation between '$g$' and '$G$'?

In the following, the phenomena which were successfully explained by the law of gravitation are :

$a$) Motion of moon around the earth

$b$) Formation of tides

$c$) Motion of an aeroplane

$d$) Force that binds us to the earth

$e$) Rotation of blades in a ceiling fan

A very long (length $L$) cylindrical galaxy is made of uniformly distributed mass and has radius $R (R<<L)$. A star outside the galaxy is orbiting the galaxy in a plane perpendicular to the galaxy and passing through its centre. If the time period of the star is $T$ and its distance from the galaxy's axis is $r$, then

A star mass $M$ (equal to the solar mass) with a planet (much smaller than the star) revolves around the star in a circular orbit. The velocity of the star with respect to the centre of mass of star-planet system is shown below:

The radius of the planet's orbit is closest to ($1 \mathrm{AU}=\mathrm{Distance} \mathrm{Earth} \mathrm{and} \mathrm{Sun}$)