ISO 



ULLY. 



. To fnd t?M ratio of Hie pon U in the 



single moveaole Pully. 



I. Suppose the parts of the string dividfl ly the pully 

 are parallel. 



Let the string ABP have one extremity fix . and 



after passing under the pully at B suppose it held by the 

 hand exerting a force P, or it may be passed over a 

 pully. The weight W is suspended by a string from the 



re Oof the pully. 

 Now the tension of the strinir A HP is the same throug 1 



< the pully is acted on by three parallel forces, 1\ 1\ 

 and IT; hence 



W 

 2P- TF= ; therefore p = 2. 



II. Suppose the portions of the string are not parallel. 



