103 WHEEL- WORK. 



12. The pilot-wheel of a boat is 3 feet in diameter ; the axle, 6 

 inches. The resistance of the rudder is 180 pounds. What power 

 applied to the wheel will move the rudder? 



13. Four men are hoisting an anchor of 1 ton weight ; the barrel 

 of the capstan is 8 inches in diameter. The circle described by the 

 handspikes is C feet 8 inches in diameter. How great a pressure 

 must each of the men exert ? 



14. With a capstan, four men are raising a 1000 pound anchor. 

 The barrel of the capstan is a foot in diameter ; the handspikes 

 used are 5 feet long ; friction equals 10 per cent of the weight. 

 How much force must each man exert to raise the anchor ? 



15. The circumference of a wheel is 8 ft.; that of its axle, 16 

 inches. The weight, including friction, is 85 pounds ; how great a 

 power will be required to raise it ? 



16. A power of 70 pounds, on a wheel whose diameter is 10 feet, 

 balances 300 pounds on the axle. Give the diameter of the axle. 



17. An axle 10 inches in diameter, fitted with a winch 18 inches 

 long, is used to draw water from a well, (a.) How great a power will 



it require to raise a cubic foot of water which weighs 62 1 Ibs. ? (6.) / f 

 How much to raise 20 litres of water ? 



18. A capstan whose barrel has a diameter of 14 inches is worked 

 by two handspikes, each 7 feet long. At the end of each handspike 

 a man pushes with a force of 30 pounds ; 2 feet from the end of 

 each handspike, a man pushes with a force of 40 pounds ; required 

 the effect produced by the four men. 



19. How long will it take a horse working at the end of a bar 7 

 feet long, the other end being in a capstan which has a barrel of 14 

 inches in diameter, to pull a house through 5 miles of streets, if the 

 horse walk at the rate of 2| miles an hour ? 



Recapitulation. To be amplified by the pupil for 

 review. 



DEFINITIONS. 



ADVANTAGES. 



RELATION TO THE LEVER. 



WHEEL 

 AND AXLE. 



FORMULAS AND LAWS. 

 FORMS. 



DRIVER. 

 FOLLOWER. 



WHEEL WORK. \ 



\ USES. 

 RELATION OF P TO W 



