

THE PENDULUM. 



f ACTED UPON BY A CONSTANT FORCE. 

 RELATION OF WEIGHT TO VELOCITY. 



LAWS- 



ILLUSTRATIVE ( Galileo's, 



Attwood's . 



APPARATUS Results tabulated 



INCREMENT OP VELOCITY WITH j Unimpeded. 

 FALL. ( Impeded. 



TAT ^ Mathematical symbols. 



IN ......... , 



O 



^^ PJX f tt hiwrshii j i N . . . . _ .. "ii-vJi .--.-,,_. 



^ Ordinary language. 



EFFECT OF INITIAL VELOCITY. 



w 

 RELATIONS TO 



( Ascending bodies ( 

 -J . -J h 



(Projectiles ....... }gth 



ECTfON IV. 



V. 



THE PENDULU M. 



137. The Simple Pendulum. A simple pen- 

 dulum is conceived as a single material particle sup- 

 ported by a line without weight, capable of oscillat- 

 ing about a fixed point. Such a" pendulum has a 

 theoretical but not an actual existence, and has been con- 

 ceived for the purpose of arriving at the laws of the com- 

 pound pendulum. 



138. The Compound Pendulum. A com- 

 pound or physical pendulum is a weight so suspended 

 as to be capable of oscillating about a fixed- point. 

 The compound pendulum appears in many forms. The 

 most common form consists of a steel rod, thin and flexible 

 at the top, carrying at the bottom a heavy mass of met:il 

 known as the lob. The bob is sometimes spherical but 

 generally lenticular, as this form is less subject to resistance 

 from the air. 



