7. The nail is the _fulcrum_ of your lever.
Now hang the pail on one of the notches about halfway between
the fulcrum and the end of the stick and put your hand on the
opposite side of the yardstick at about the same distance as
the pail is from the fulcrum. Raise and lower the pail several
times by moving the opposite end of the lever up and down. See
how much force it takes to move the pail.

Now slide your hand toward the fulcrum and lower and raise the
pail from that position. Is it harder or easier to lift the
pail from here than from the first position? Which moves
farther up and down, your hand or the pail?

Next, slide your hand all the way out to the end of the
yardstick and raise and lower the pail from there. Is the pail
harder or easier to lift? Does the pail move a longer or a
shorter distance up and down than your hand?

If you wanted to move the pail a long way without moving your
hand as far, would you put your hand nearer to the fulcrum or
farther from it than the pail is?

[Illustration: FIG. 27. The yardstick is a lever by which he lifts the
pail.]

[Illustration: FIG. 28. A lever with the weight between the fulcrum
and the force.]

Suppose you wanted to lift the pail with the least possible
effort, where would you put your hand?

Notice another fact: when your hand is at the end of the
yardstick, it takes the same length of time to move a long way
as the pail takes to move a short way. Then which is moving
faster, your hand or the pail?

EXPERIMENT 19. Put the end hole of the yardstick on the nail,
as shown in Figure 28. The nail is still the fulcrum of your
lever. Put the pail about halfway between the fulcrum and the
other end of the stick, and hold the end of the stick in your
hands.

Raise and lower your hand to see how hard or how easy it is
to lift the pail from this position. Which is moving farther,
your hand or the pail? Which is moving faster?

Now put your hand about halfway between the fulcrum and the
pail and raise and lower it. Is it harder or easier to raise
than before? Which moves farther this time, your hand or the
pail? Which moves faster?

If you wanted to make the pail move farther and faster than
your hand, would you put your hand nearer to the fulcrum than
the pail is, or farther from the fulcrum than the pail? I