On Jul 13, 10:22*pm, Smitty Two wrote:
In article
,
*harry k wrote:

Nope. *It is strobing. *In some of the old films you can see a wheel
go backwards, slow, forwards. *That is caused by the wheel speed
changing.

Harry K

Have you actually seen the commercials, Harry? I'd be surprised if you
saw them and stuck by your wagon wheel effect hypothesis. In the
screwdriver commercial, it doesn't matter whether you look at the chuck,
the driver bit, or the screw, it's rotating the wrong way, quite clearly
and a very stable rate.

Of course it is an so is every part of it, they are all fixed and
therefore rotate together. Vary the speed of the drill and you would
see the rotation slow, speed up or even reverse direction.

You must have missed that demonstration in the HS physics course.

Harry K