According to Malcolm Hoar :
In article ,
(Doug Miller) wrote:

Oh, come on! The piece of wood in the first video travelled "just a few feet"
because it hit a sheet of plywood on the opposite side of the shop! Can't you
imagine that it would have gone much farther than it did, if there
hadn't been
something in the way? Good grief.

It didn't penetrate the plywood, did it?

It might have if the plywood was mounted so that it couldn't
move on impact, and plywood is tougher than years old brittle
cedar shingle or drywall.

Note also that this is a different kind of kickback than you'd
see with ripping a chunk of trim (the photo wasn't good enough
to tell for sure, but it looked as if it may have been ripped).

A lot of the energy imparted to the chunk of plywood was
rotational. Not to mention that the cross-sectional area
in the direction of travel was more than the trim would be.

A kickback like that is relatively safe to demonstrate. A
pure longitudinal kickback is more dangerous, and imparts
virtually all of the energy in the direction of travel.

If you're ripping a piece of trim that has an convex back,
it'd just take the trim rotating a bit (around the long
axis) to jam between the blade and fence and get flung straight.

The OP's molding penetrated shingles, insulation and
drywall. And that was at a range of 50ft!

A human arm can do it easily with a blunt spear, and could
probably also do it if the chunk of trim was thrown carefully
enough to stay relatively straight. A table saw has
more power than a human arm.
--
Chris Lewis,

Age and Treachery will Triumph over Youth and Skill
It's not just anyone who gets a Starship Cruiser class named after them.