1 08 Domestic Science 



5. In a determination of the specific gravity of brine, the 

 following observations were made : 



Weight of flask .> 36-70 g. 



filled with water 89 -67 g. 



brine 92*45 g. 



Find the specific gravity of the brine. 



6. The specific gravity of a sample of olive oil is 0'915. What 

 will be the apparent loss of weight of a brass cube of 3 cm. edge 

 when weighed in the oil ? 



7. A lump of aluminium weighs (a) in air, 30 g., (b) in water, 

 18*4 g., (c) in chloroform, 12'6 g. Find the specific gravities of the 

 metal and the chloroform. 



8. How much air will enter a room 20 ft. long, 16 ft. 9 in. wide, 

 and 10 ft. high, if the pressure of the air varies from 29 '5 in. to 

 30 '1 in., as measured by the barometer ? 



9. A partially inflated bladder is placed inside a stout-walled 

 glass flask, and the air is gradually exhausted from the flask by 

 means of an air-pump. What would you expect to happen to the 

 bladder ? Give reasons for your opinion. 



10. Why is it easier to float in sea-water than in fresh water ? 



11. When the tube of a Torricellian barometer is gradually 

 inclined from the perpendicular, the level of the mercury surface 

 approaches the closed end of the tube until finally the tube is com- 

 pletely filled with the liquid. How do you account for this ? 



CHAPTER VII 



CENTRE OF GRAVITY 



66. When discussing the meaning of the terms 

 " weight " and " gravity " in Chapter in, it was men- 

 tioned that the attraction between two bodies is 

 increased when the distance between their centres of 



