# Gravitational tidal force problem

if we have spherical mass held by its self-gravity, there will be a limit to distance - let's say it is $r$ - that the center of this body may approach a much more massive body (lets we call $M$ body).

Our spherical mass here would be held - as I understand - by gravitational tidal force. But the question is what is the distance $r$ between to masses his effect will hold?

$$r=\left(\frac{2M}{m} \right)^{1/3} \times R$$

$m$ - Spherical body mass

$R$ - Spherical body radius

$M$ - Massive body

I guess this is the equation for this limit, but I don't understand the conditions of this limitation.