266 REVIEW. 



28. (a.) Supposing we have two Leyden jars, one charged on the 

 inside with positive electricity, and the other with negative on the 

 inside ; the two jars being insulated, can the jars be discharged by 

 connecting the inner coats ? (&.) Give reasons for your answer. 



29. In a vessel having the dimensions of a cubic foot, sulphuric 

 acid (sp. gr. 1.83) stands eight inches high ; give the pressure on 

 the bottom and each side. 



30. The lever of a hydrostatic press is six feet long, the fulcrum 

 being at the end, and one foot from the piston rod. The diameter 

 of the tube is one inch ; that of the cylinder ten inches. The power 

 is 25 Ibs. ; give the effect. (See Appendix A.) 



31. What would a cubic foot of coal (sp. gr. = 2.4) weigh in a 

 solution of potash (sp. gr. = 1.2)? 



32. (a.) Define equilibrium and its kinds. (&.) Give examples. 

 (c.) How does the centre of gravity of any system, acted upon by 

 an exterior force, move ? (d.) Give an example. 



33. (a.) Figure a simple barometer. (&.) Explain why the mer- 

 cury stands above its level, (c.) What atmospheric pressure will 

 sustain a column of mercury 24 inches high ? 



34. (a.) How is it proved that air has weight? (b.) What is the 

 weight of air in a room 30 ft. long, 20 ft. wide and 10 ft. high ? 



35. When a 1000 gram flask, containing 700 g. of water, was 

 filled with the fragments of a mineral, it weighed 1450 g. Give 

 the specific gravity of the mineral. 



36. A tank measuring 1 metre each way is filled with water : what 

 will be the pressure on the bottom and sides ? 



37. (a.) What is meant by kinetic energy? (6.) By potential 

 energy ? 



38. Two inelastic bodies are moving in opposite directions, one 

 weighing 31 grams and having a velocity of 24 meters per second, 

 the other weighing 22 grams and having a velocity of 18 meters 

 per second: what is the united energy (a.) before, and (6.) after- 

 impact ? 



89. Regarding the same bodies as moving in the same direction, 

 what would be the energy (a.) before, and (&.) after impact ? 



40. (a.) Draw a simple figure showing the essential parts of an 

 air pump, and (6.) explain the process of forming a vacuum, (c.) If 

 the capacity of the barrel be \ that of the receiver, how much air 

 will remain in the receiver at the end of the fourth stroke of the 

 piston? and (d.} what would be its elastic force compared with that 

 of the external air ? 



41. Discuss briefly the connection between electric separation and 

 the more ordinary forms of energy. 



