APPENDIX of QUESTIONS. 1.-GENERAL PROPERTIES OF MATTER AND UNIVERSAL ATTRACTION. 1. What is the difference between a chemical and a physical action? Give some examples of each. 2. What are the three forms in which matter exists? 3. By what properties of the molecules do we account for the existence of matter in three different forms? 4. Give instances of one and the same body being met with in the three different forms which matter assumes. 5. State and explain what is meant by inertia. 6. Explain the meaning of the terms (a) uniform motion; (b) uniformly accelerated motion; (c) retarded motion; and state how such effects are produced. 7. What effect on the motion of a ship is produced according as the bow or the stern guns are fired? 8. Give an accurate explanation of the process of freeing a carpet from dust by beating it with a stick. 9. Give instances of cases in which it is desired to increase friction ; and others in which it is diminished. 10. Give some examples of rolling friction, and some of gliding friction. II. Why is the bob of a pendulum thinner at the edge than in the middle? 12. How can it be shown that a coin and a feather fall with equal velocity? 13. In rowing, what is the advantage of feathering the oars? 14. A plummet, the string being held in the hand, is immersed in a current of water, and the string ultimately settles in a somewhat slanting position. Explain by a diagram the nature and action of the forces which determine the position of the string. 15. If while a steamer is steaming along the smoke rises vertically, what conclusion can you draw as to the state of the atmosphere? 16. Give some instances of the practical application of centrifugal force. 17. How is it that a circus rider always leans towards the centre of the circus? If he increases his speed, does he lean more, or less, than he did before? 18. When a man, standing on a horse, which is going at great speed, jumps vertically upwards, what is the direction of the path which his body takes? 19. A ball is thrown vertically upwards, in an open railway waggon, travelling at high speed: What is the general appearance of its path to a person who sees this as the train passes by? 20. When a circus rider jumps through a hoop, in what direction does he spring? 21. In the rotation of the vanes of a windmill, is the velocity of every point on the vane the same? If not, where is it greatest? 22. Explain why and under what circumstances drops of water fly from the surface of a grindstone which is being rapidly turned? 23. Explain why and in what direction drops of water fly from the wheels of a carriage running along a wet road. 24. How is corn separated from chaff in a mill? 25. Account for the fact that it is as easy to play ball on a rapidly moving steamer as it is on land. 26. If at the equator a straight hollow tube were thrust vertically down towards the centre of the earth, and a heavy body were dropped through the centre of this tube, it would soon strike one side. Find which, and give a reason for your reply. 27. If a ball is allowed to drop from the top of a high tower, in what position does it fall in reference to the base of the tower? 28. If two porters, A and B, carry a cask hung to a pole resting on their shoulders, what is the proportion which each porter bears (a) When the cask is half-way between them; (b) When it is at a distance from A twice that which it is from B; (c) When it is at four times as far from B as it is from A; 29. Why is a finger caught in the hinge of a shutting door so severely crushed? General Properties of Matter. 599 30. Explain the mechanical advantages of steel nippers in drawing nails from wood. 31. Apply the principle of the lever to explain the cracking of a nut by the teeth. 32. In lifting a weight with the hand, show that the lower part of the arm becomes a lever of the third kind. 33. What is the difference between gravitation and gravity? 34. How can you ascertain whether a table is quite horizontal, and whether a wall is quite vertical? 35. Why is it easier for a man to carry a pail of water in each hand than to carry only one? 36. A cart laden with stones may go safely on a road one side of which is higher than the other; whereas if it were loaded with hay it might be overturned. Explain this. 37. Why are lamps and candlesticks loaded with weights at the base ? 38. How can a body be accurately weighed by means of a balance which is not itself accurate? 39. Why are stepped stairs used in houses instead of a smooth inclined plane? 40. What do we understand by the length of the pendulum in an ordinary clock? 41. How is the ordinary pendulum regulated? 42. What alteration must be made in the length of a seconds pendulum which swings correctly at the sea-level, if it is to be brought to the top of a hill? 43. Explain the manner in which the oscillations of the pendulum may be applied to determining the figure of the earth. 44. What is the difference between cohesion and chemical affinity? What the difference between adhesion and chemical affinity? 45. What is the difference between cohesion and adhesion? 46. Give some illustrations of phenomena in which the forces of cohesion, of adhesion, and chemical affinity come respectively into play. 47. Mention some substances which have, in a pre-eminent degree, severally the properties of hardness; of malleability; of elasticity; and of brittleness. 48. Describe the construction and explain the action of the humming top. II. ON LIQUIDS. 1. When a stream of water falls into a basin, drops spurt out; of what property of water is this a proof? 2. What is the essential difference between liquids and gases? 3. Is a flood-gate which keeps the sea out of a dock exposed to more or to less pressure than one which keeps out a lake or river? The depth below the surface of the water is supposed to be the same in each case. 4. Under what conditions does the principle of the equality of pressures of liquids in communicating vessels no longer hold? 5. Illustrate and explain some of the principal phenomena of capillary attraction. What forms do the surfaces of mercury and of water assume in narrow tubes? 6. If one end of a skein of silk be placed in a liquid contained in a vessel, and the other hangs over the side, the liquid is found after some time to be empty. How may this have been brought about? 7. Describe experiments showing the porosity and elasticity of solids, and also of liquids. 8. Describe an experiment which shows that different liquids adhere to solids with varying degrees of force. 9. What are the causes which prevent a jet of water from reaching the height of the water in the reservoir from which it is fed? 10. Why can water-spiders and many other insects run on the surface of the water? II. In pouring water out of a jug, why is some apt to trickle down below the spout? 12. Why is writing with ink more permanent than with lead pencil? 13. Describe a simple method of determining the exact volume of any body of irregular shape; a stone, for example. 14. A small cubical box full of water is placed on a large piece of cork which is floated on water. Explain what happens when a hole is made in one side of the box. 15. What metals float on mercury? what metals sink? 16. If a pipe from a gutter fits water-tight into the top of a water butt, what pressure must be allowed for on the bottom of the butt? 1. What is the main distinction between gases and liquids? 2. Why is atmospheric air chosen as the type of gaseous bodies? 3. How can you prove the existence of an atmosphere ? 4. Describe and explain the action of some apparatus which depend on the pressure of the atmosphere. 5. How is the pressure of the atmosphere measured? 6. How can you show that gases have weight; elasticity? 7. Demonstrate experimentally the elasticity of air. 8. What experiment proves that the atmospheric pressure at any given level is transmitted equally and in all directions? 9. How can you tell whether the Torricellian vacuum of a barometer is perfectly free from air? 10. Explain how the amount of the atmospheric pressure in pounds is found; and why we are unconscious of its action on our bodies. II. Is it necessary that a barometer tube be everywhere of the same diameter? Must a thermometer tube have the same calibre throughout? Give reasons for your answers. 12. Explain the principle of the application of the barometer to the measurement of the heights of mountains. 13. Explain the principle of the use of the barometer as an indicator of the state of the weather. 14. Explain the manner in which water is raised in a pipette or in a wine-taster. 15. How do you measure the degree of rarefaction in a receiver attached to an air-pump? 16. Why does a bubble of air liberated at a considerable depth in water gradually increase in size until it reaches the surface? 17. Supposing an air-tight bladder, containing a cubic foot of air, at a depth of about thirty feet in the sea, to be brought to the surface, what would it measure then? 18. If a pound of atmospheric air under the ordinary atmospheric pressure measures 13.07 cubic feet, what will it measure under a pressure of 29.2 inches? |