TRANSMISSION OF POWER 301 



2. Two gears have pitch circles of 85 in. and 17 in. in diameter 

 respectively. What is the ratio of their speeds? What is the ratio 

 between the number of teeth in their gears? 



3. A 48-tooth gear drives a 120-tooth gear. What is the ratio 

 of their speeds? 



4. Two shafts are connected by gears. One turns 55 times a 

 minute, and the other turns 1 1 times a minute. If the smaller gear 

 has 32 teeth, how many teeth has the larger gear? 



5. Three gears of a train have 69, 30, and 74 teeth respectively. 

 If the 69-toothed gear makes 100 R. P. M., how many R. P. M. will 

 the 74-toothed gear make? Figure the result and make a sketch 

 of the gears, showing by arrows the direction in which each turns. 



6. A train of gears is made up of 6 gears having teeth as follows : 

 46, 60, 32, 72, 56, and 48. While the first gear in the train makes 

 10 turns, how many turns will the last gear make? 



7. What two gears will give a ratio of speeds so that the driver 

 will make -} J- as many turns as the follower; in other words, while 

 the driver makes 13 turns the follower will make 14? 



8. A horse used for moving a house walks around in a 12-ft. 

 circle pulling 800 Ibs. on a capstan bar. If the drum of the capstan 

 is 24 in. in diameter, how much pull will the rope exert on the 

 house? 



