"Harry K" wrote in message
m...

Ok. mentally tie the rope to the top anchor. What is the pull? Answer
20 lbs. Do you agree with that?

Now extend the rope to the bottom and tie it. What has changed?
Nothing.

Of course if you are adamant that 20 lbs just magically appear you
could go down to the school and ask the physics teacher. He will
probably show you the identical experiment with identical (altho more
acccurate) results I did.

Waiting your comment.

Harry K


Sure you are right if you are talking about this,

20
|
|
20
But we have been talking about this,

40
/\
/ \
/ \
20 20

Two totally differant deals!
With a load supportted by a rope that goes through a pulley shown imediately
above, there needs to be a equal force on the opisite end of the rope to
balance the load. The addition of the load used to balance the weight adds a
the additional load at the pulley.
Greg