THE LEVER 



463 



a small board so that its edge shall be even with the edge of the 

 table. Weight or clamp the board to the table. Into the edge of 

 the board drive a round-finish, small-headed nail so that it will 



FIGURE 138 



project horizontally over the edge of the table. Slip the nail 

 through the center hole of the meter stick. (Figure 138.) 



Hang a weight of 400 g. from the first decimeter hole. Find 

 out how much weight will be required at each of several holes on 

 the other side of the nail in order to 

 balance the 400 g. weight. In each case, 

 multiply the weight on each side of the 

 nail by its distance from the nail and 

 compare the results. Lift one end of the 

 meter-stick 10 cm. above the edge of the 

 table, and note how far each weight 

 moves. Multiply each weight by the 

 distance it moved up or down, and com- 

 pare the results. 



(6) Attach a small spring balance by a 

 short string to one of the end holes of the 

 meter-stick. Slip the nail through the 

 hole next to it. Hang a weight of 400 g. 

 from any one of the other holes. Pull 

 down on the spring balance until the 

 meter-stick is in a horizontal position. 

 Note the pull on the spring balance and 

 make the same computations as in (a). Repeat the experiment and 

 computations by hanging the weight from several different holes. 



(Exact accuracy in these experiments would require a considera- 

 tion of the weight of the meter-stick itself, but for the purposes of 

 this experiment, results will be nearly enough accurate without this.) 



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