6o 



Common Science 



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 ? 



