If the two are dropped in a vacuum, the human item will explode.

Otherwise it will depend on how closely the human resembles an anvil and the resulting drag co-efficient of air against said items.

A very pointy man might be able to achieve the given inverted hanging, a fatter man would survive until ground impact.

In this case, I think the term "terminal velocity" would be doubly appropriate. But there is a lot of conjecture along the way.

Take a 100kg man (short and fat, or big and muscular - your call). The skydiver pose gives a terminal velocity about 120mph, but you can get to about 200mph in the head-down, arms-back layout. I assume slipstreaming behind an anvil does not affect the drag much.

It takes a big blacksmith to lift an anvil, so I guess 50kg. Iron is about 5.5 times denser than people. I know WW2 bombs exceeded the speed of sound and were stabilised by being spun with offset tail fins. I don't see an anvil breaking the sound barrier, but I imagine 500mph is possible.

If you tie anvil to body, they fall at a common velocity v. I believe wind resistance is proportional to the square of the speed. So I think the wind resistance of the anvil at v is 50 * v * v / (500 * 500); of the body is 100 * v * v / (200 * 200); and at terminal velocity this totals to their combined weight of 150kg. This solves for v = 235.7.

Put v back in the terms above, and the anvil wind resistance becomes 11.1kg and the body 138.9kg. The tension in the rope is therefore 38.9kg - holding up the remaining weight of the anvil, and pulling down against the extra resistance of the body.

Provided there is not an initial jerk, and the slip knot is not too effective, this ought not to be fatal, and the victim might be able to pull in some slack, tie the rope to the parachute harness (leaving enough slack that the anvil hits first), and pull the chute to save his life.

Execution by hanging relies on the "drop" to break the neck, not on strangulation. There was a table produced of the drop required for various body weights that would break the neck but not rip off the head. Somewhere between 5 and 9 feet might be used.

In WW2, some troops parachuted with Rudge motor scooters hung from their harnesses. That must have been some fun too. They fell much faster than usual, but the Rudge was on a 50' rope which let the parachute slow the man after the bike hit.

Finally, at Brooklands there is a 1930's car equipped with a W-12 aircraft engine of about 1000hp for testing parachutes. Reputedly, it could be driven at 150mph - with a fully deployed chute attached behind it.