206 Domestic Science 



Exercise for Student. 



Assuming the Kinetic Molecular Hypothesis, try to account for 

 the phenomena generalised in the statement known as Boyle's Law. 



QUESTIONS 



1. From what height must a weight of 1 ton be dropped if all 

 the kinetic energy generated during its fall is to be enough to raise 

 the temperature of 2 Ib. of water from 32 F. to 212 F. ? 



2. How much energy, expressed in kilogram-metres, is given 

 out while 548 g. of water cool from 65 to 8 ? 



3. How much energy in the form of heat must be supplied to 

 an iron cube with edges 6 cm. long, in order to raise its temperature 

 from 15 to 150 ? (Sp. heat of iron= 0'114.) 



4. Find the height to which a stone, weighing 500 g., could be 

 raised, if all the energy set free during the condensation of 10 g. 

 of steam could be expended in raising it. 



5. The burning of 1 g. of carbon produces 8080 calories. What 

 weight of ice could be melted by the burning of 185 g. of carbon ? 



CHAPTER XIII 



AIR 

 Its Nature and Chief Constituents 



139. We have learnt in the preceding chapters that 

 air is a gas and has both volume and weight. In this 

 chapter the nature of air will be further investigated. 

 To this end we will first perform the following simple 

 experiment. 



EXPERIMENT 75. Affix a short length of candle 

 (the small candles used on Christmas trees are most 

 suitable) to a wooden block by lighting the candle, 



