EXAMPLES. 43 



2. If the area of a (Fig. 4) be a square inch, and if it be 

 pressed by a force of 15 Ibs., what pressure * will this trans- 

 mit to the piston A if its diameter be 10 in. ? 



Ans. Pressure on A = 1178 Ibs. 



3. If the diameter of a be 4 in., and if the pressure on it 

 be 185 Ibs., what pressure will be exerted on A if its area is 

 one square foot? Ans. Pressure on A = 2120 Ibs. 



4. If the area of a be 20 square inches, and if it be 

 pressed by a force of 360 Ibs., find the diameter of A so 

 that it shall be pressed upwards by a force of 10 tons (one 

 ton = 2240 Ibs.) Ans. Diameter of A = 39.8 in. 



5. If the diameter of A (Fig. 3) be one inch, and if the 

 surface at E be a square whose side is one-quarter of an 

 inch, find the pressure transmitted to E if that on A be 

 10 Ibs. Ans. Pressure on E = 0.795 Ibs. 



6. If the area of A be 2 sq. in., and the pressure on it 

 56 Ibs., find the pressure transmitted to a surface at E, the 

 area of which is a triangle whose base is | of an inch, and 

 whose height is -fa of an inch. 



Ans. Pressure on E = 0.42 Ibs. 



7. A cylindrical pipe which is filled with water opens 

 into another pipe the diameter of which is three times its 

 own diameter ; if a force of 20 Ibs. be applied to the water 

 in the smaller pipe, find the force on the open end of the 

 larger pipe which is necessary to keep the water at rest. 



Ans. 180 Ibs. 



8. Required (1) the pressure on the sides of a cubical 

 vessel filled with water, and (2) the pressure on the bottom, 

 the side of the vessel being a ft. (Art. 10). 



Ans. (1) 125a 3 Ibs. ; (2) 62. 5a 3 Ibs. 



9. A cylindrical vessel is filled with water ; the height of 

 the vessel is a ft, and the diameter of the base d feet. 

 Find (1) the pressure upon the side and (2) the pressure on 

 the bottom. Ans. (1) Slfrtfd ; (2) 15f7ra#. 



* In the first seven examples, the weight of the liquid Itself is not considered. 



