Mechanical advantage, or just a redirection of force?

[garyTheSnail]

TL;DR

A question about leverage

In the following image, does the 4 x 4 post offer a mechanical advantage or does it just redirect force? Thank you in advance.
Reference video:

 

[Baluncore]

It offers both a mechanical advantage and redirects the force. The steeper the post, and the closer its foot is to the stump, the greater is the advantage. The limit is the stretch of the rope.

Once the stump has lifted, the final roots must be pulled, which requires less force, so there is advantage in moving the foot away, to increase the speed, while reducing the advantage.

 

[garyTheSnail]

It offers both a mechanical advantage and redirects the force. The steeper the post, and the closer its foot is to the stump, the greater is the advantage. The limit is the stretch of the rope.

Once the stump has lifted, the final roots must be pulled, which requires less force, so there is advantage in moving the foot away, to increase the speed, while reducing the advantage.

Thank you for the information. Would the top of the post along with its movement give a similar mechanical advantage as a single pulley suspended from above? My thought is the rotational movement of the cable around the pulley is somewhat similar to the arc movement of the post top supporting the cable. Or am I wrong?

 

[renormalize]

Your diagram needs a better looking wench.

 

[garyTheSnail]

Doh!

 

[Baluncore]

Would the top of the post along with its movement give a similar mechanical advantage as a single pulley suspended from above?

No. A pulley would turn freely but remain in position, which will equalise the tension on both sides of the pulley.

As shown, the chain is locked to the top of the pole, so the sum of the forces at the top of the pole gives different tension forces in the chain on either side.

If you had a pulley at the top of the pole, the pole would fall over due to unbalanced forces.

 

[garyTheSnail]

Thank you again.