At the event horizon, the black hole’s gravity is so powerful that no amount of mechanical force can overcome or counteract it.
Even light, the fastest-moving thing in our universe, cannot escape – hence the term “black hole.”
The radial size of the event horizon depends on the mass of the respective black hole and is key for a person to survive falling into one. For a black hole with a mass of our Sun (one solar mass), the event horizon will have a radius of just under 2 miles.
The supermassive black hole at the center of our Milky Way galaxy, by contrast, has a mass of roughly 4 million solar masses, and it has an event horizon with a radius of 7.3 million miles or 17 solar radii.
Thus, someone falling into a stellar-size black hole will get much, much closer to the black hole’s center before passing the event horizon, as opposed to falling into a supermassive black hole.
This implies, due to the closeness of the black hole’s center, that the black hole’s pull on a person will differ by a factor of 1,000 billion times between head and toe, depending on which is leading the free fall. In other words, if the person is falling feet first, as they approach the event horizon of a stellar mass black hole, the gravitational pull on their feet will be exponentially larger compared to the black hole’s tug on their head.
The person would experience spaghettification, and most likely not survive being stretched into a long, thin noodlelike shape.