HYDROSTATICS. 127 



EXERCISES. 



1. What will be the pressure on a dam in 20 feet of water, the 

 dam being 30 feet long ? 



2. What will be the pressure on a dam in 6 m. of water, the dam 

 being 10 m. long ? 



3. Find the pressure on one side of a cistern 5 feet square and 12 

 feet high, filled with water. 



4. Find the pressure on one side of a cistern 2 m. square and 4 m. 

 high, filled with water. 



5. A cylindrical vessel having a base of a sq. yd. , is filled with 

 water to the depth of two yards. What pressure is exerted upon 

 the base? 



6. A cylindrical vessel having a base of a sq. m. is filled with water 

 to the depth of two meters. What pressure is exerted upon the 

 base? 



7. What will be the upward pressure upon a horizontal plate a 

 foot square at a depth of 25 ft. of water ? 



8. What will be the upward pressure upon a horizontal plate SO 

 cm. square at the depth of 8 m. of water ? 



9. A square board with a surface of 9 square feet is pressed 

 against the bottom of the vertical wall of a cistern in which the 

 water is 8| feet deep. What pressure does the water exert upon 

 the board ? 



10. A cubical vessel with a capacity of 1728 cubic inches is two- 

 thirds full of sulphuric acid, which is 1.8 times as heavy as water. 

 Find the pressure on one side. 



11. A conical vessel has a base with an area of 237 sq. cm. Its 

 altitude is 38 cm. It is filled with water to the height of 35 cm. 

 Find the pressure on the bottom. Ans. 8295 g. 



12. In the above problem, substitute inches for centimeters, and 

 then find the pressure on the bottom. 



13. What would be the total liquid pressure on a prismatic vessel 

 containing a cubic yard of water, the bottom of the vessel being 2 

 by 3 feet ? 



14. The lever of a hydrostatic press is 6 feet long, the piston-rod 

 being 1 foot from the fulcrum. The area of the tube is one-half 

 square inch ; that of the cylinder is 100 square inches. Find the 

 weight that may be raised by a power of 75 Ibs. 



15. What is the pressure on the bottom of a pyramidal vessel 

 filled with water, the base being 2 by 3 feet, and the height, 5 feet? 



16. What is the pressure on the bottom of a conical vessel 4 feet 

 high filled with water, the base being 20 inches in diameter ? 



