PLUMB LINE AND PENDULUM 7 



cylinder measure out carefully 25 cu. cm. of water. Get the 

 weight of an empty dish, such as a measuring cup ; then pour all 

 of the water into it. Weigh the cup and the water, and cal- 

 culate the weight of the 25 cu. cm. of water. How much 

 would 1 cu. cm. of water weigh, according to your result? How 

 much would a liter of water weigh? What is the accurate 

 weight of 1 cu. cm. of water at 4 C.? Of a liter? 



From the result of Exercise 3 tell how many cubic centimeters 

 there are in a cupful. How many grams of water are there, 

 consequently, in a cupful? From the Appendix (text) find out 

 how many grams there are in an ounce. How many ounces 

 of water, then, in a cupful? How many ounces in a pint? 



Is it true that 



"A pint's a pound, 

 The world around"? 



What fraction of a pint does a "4-oz." bottle hold? 

 Record your results thus : 



Wt. of cup + 25 cu. cm. of water = g. 



Wt. of cup alone = g. 



Wt. of 25 cu. cm. of water = g. 



Wt. of 1 cu. cm. of water = g. 



Accurate wt. of 1 cu. cm. water at 4 C. = g. 



Accurate wt. of 1 liter water at 4 C = g. 



Wt. of water in a cupful = g. 



Wt. of water in a cupful = oz. 



Wt. of water in a pint = oz. 



EXERCISE 5 

 PLUMB LINE AND PENDULUM 



Apparatus. A small, dense object, such as a metal ball, a bullet, a 

 stone, or a key; also some thread. 



