130 



LABOKATORY MANUAL 



Locate on the apparatus the fulcrum, the power, 

 weight, power-arm, and weight arm. 



Shift the weight on the bar, and record the readings 

 on the balance with the weight at 0, 6, 12, 18, 24, 30, 

 and 36 inches from the fulcrum. 



Tabulate your readings as follows : 



How do the two product columns compare? What 

 class of lever is used in this exercise? 



Of what mechanical advantage is the lever in lifting 

 the 500 gm. weight as shown by the reading at the 

 6-inch point? 



How would you convert this apparatus into a third 

 class lever? Into a first class lever? 



From the results of this exercise what law can you 

 deduce for levers? 



Exercise 87. Muscles. (Demonstration.) 

 Object: To determine the structure and action of 

 muscles. 



Frog 



Dissecting pan 

 Scalpel 



Apparatus 



Scissors 

 Needles 



