PHYSICS 



Monday 3-45-5-45P- m - 



A teacher's certificate covering the laboratory instruction must be presented as part 



of the examination. 



Answer ten questions as indicated below. No extra credit will be given for more 



than ten questions. 



GROUP A 

 Omit one question from this group 



1. Explain the meaning of the terms mass, density and weight. For what 



two reasons would the apparent weight of a body change if it were taken 

 from the earth's pole to the equator ? 



2. Resolve a force of 100 Ibs. into two components, acting at right angles to 



each other, one of the components to be three times as large as the other. 



3. A straight uniform bar, 102 centimeters long and weighing 150 grams, is 



supported at its ends and a kilogram weight is suspended from the bar 

 22 centimeters from the left-hand end. Calculate the total pressure on 

 the right-hand support. 



4. When the barometer stands at a height of 75 centimeters what is the total 



atmospheric pressure upon a man's body, the area of surface being taken 

 as 1.2 square meters? (The density of mercury is 13.6.) 



GROUP B 

 Omit one question from this group 



5. (a) How does a "noise" differ from a musical sound? 



(b) Explain the formation of beats as they are sometimes observed when 

 two tuning forks are sounded simultaneously. What determines the 

 number of beats per second ? 



6. On a day when the temperature was 20 C. a gun was fired and, after 4 sec- 



onds, the echo from a distant hill was heard. How far away was the hill ? 



GROUP C 

 Omit one question from this group 



7. (a) Explain the three methods of transferring heat known as conduction, 



convection, and radiation. 



(b) Describe some experiment which shows that water has low conduc- 

 tivity for heat. 



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