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tity of heat."

(b) What facts show that heat is a form of energy?

13. (a) A lens having a focal length of 10 inches is used to project a real image of an object on a screen 20 feet distant from the lens. What must be the distance from object to lens, and what is the relation of the size of the image to the size of the object?

(b) Distinguish between "real image" and "virtual image."

14. (a) What is the nature of light? Give what evidence you can in support of your answer.

(b) What information in regard to a body can be obtained by examining the spectrum of the light which it emits?



(Omit one question).

1. Establish the law of the composition of forces.

2. A block, starting from rest at the top of an inclined plane which has a slope of 30 degrees and a length of 5 metres, requires 4 seconds to reach the bottom; calculate the coefficient of friction, and the work done against friction.

3. A beam, 28 feet long, and having a mass of 200 kilograms, rests on two posts, the points of support being respectively 5 and 19 feet from one end of the beam. Calculate the load supported by each post.

4. A fly-wheel, having practically all of its mass concentrated in the rim, is set in rotation by a weight suspended from a rope which unwinds from the surface of the wheel. What will be the angular velocity of the flywheel 10 seconds after the driving-weight is released, if the diameter of the wheel is 2 metres, and its mass is twice that of the driving-weight?

5. (a) A piece of metal floating on mercury is one-half immersed; another liquid is poured on top of the mercury and the metal is then only two-fifths immersed in the mercury; determine the density of the upper liquid, given that the density of mercury is 13.6.

(b) Establish the principle used in (a).

6. Explain the existence of surface tension, and prove that the height to which a liquid will rise in a capillary tube is inversely proportional to its radius.


(Omit one question).

7. The small tube of a Bunsen ice calorimeter has an internal diameter of .5 mm. A small piece of gold weighing .5 gm. is dropped into the calorimeter and the mercury in the tube moves 2.31 cm. What is the specific heat of gold? The density of ice is .917.

8. If 4490 cc. of a gas at 101° C, under a pressure of 754 mm. of mercury have its pressure increased to 821 mm. and its temperature raised to 225°, what will be the new volume?

9. (a) What is meant by the term Mechanical Equivalent of Heat?


(b) Explain one method of determining this quan

(c) What is meant by the Critical Point of a sub


10. (a) Draw diagrams to illustrate Huyghens' Principle for the following cases: (i) Reflection of a plane wave from a plane surface. (ii) Refraction of a plane wave passing from glass to air.

(b) The index of refraction from air to glass is 1.5. A flat plate of glass with parallel faces is laid over a spot on a piece of paper. How far from the upper surface of the glass will the spot appear to be?

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cal concave mirror, where r1 and r, are the distances of the object and image from the mirror, and ƒ is the focal length of the mirror.

12. (a) Explain the phenomenon known as Newton's Rings.

(b) A slice of doubly refracting crystal cut parallel to the optic axis is placed between crossed nicols and light appears. Explain.



(Answer ten questions only).

1. Mention the points of similarity in the structure of seeds, buds, runners, bulbs, corms, and bulblets, and give a reason for any dissimilar arrangement or structure.

2. Define carefully each of the following functions:photosynthesis, transpiration, respiration, digestion, and assimilation, naming the structures chiefly associated with each.

3. Describe the foliage leaf under the headings:-general shape, internal structure, and the reason for each peculiarity.

4. Compare in the structure of root, of stem, and of leaf, a corn plant, a pumpkin plant, and a submerged pond weed, giving a reason for each difference found.

5. Why and how do plants climb? Name examples of each method.

6. What are the plans, the habits, and the modifications by which plants survive in very dry conditions?

7. Describe the zonal arrangement of plants in and about a pond.

8. How do our plants prepare for winter conditions? 9. Define carefully a plant society, illustrating your answer by describing one of the hydrophytic societies.

10. Discuss the uses of the plant kingdom to the animal kingdom, and vice versa.

11. Describe the structure and reproduction of Bread Mold (Mucor or Rhizopus), and of a fern.

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