HARNESSING 'ENERGY 



163 



EXPERIMENTS OR DEMONSTRATIONS WHICH WILL 

 HELP ANSWER THE PROBLEM QUESTIONS' 



Experiment 111. Where does 

 steam get its energy? 



Grease a solid rubber stopper 

 which fits into a test tube. Place 

 about a half inch of water in the 

 test tube and insert the rubber 

 stopper, but do not push it in 

 very tightly. Place the test tube 

 in a holder and hold over a 

 flame. Point the stopper away 

 from you and observe results. 



The stopper was . the test 



tube. The force causing this 



came from the of the 



steam. The steam secured its 



FIG. 265 energy from the energy of 



the . 



Experiment 112. How may the energy of steam be 

 harnessed by the steam turbine? 



Bend an eight-inch piece of glass tubing to a right angle 



and draw one end of it down 

 to a jet. Insert the other end 

 in a one-hole rubber stopper 

 which fits into a flask of at 

 least 500-cubic-centimeter ca- 

 pacity. From a piece of quar- 

 ter-inch wood cut a circle 

 four inches in diameter. With 

 a coping saw cut little slots 

 every inch around the cir- 

 cumference of this piece. 

 These should be about a half 

 inch deep. See B in Figure 

 267. Now from a can cut lit- 

 tle pieces of tin of the shape 

 shown at C in the illustra- 

 tion. These should be about 

 an inch long, a half inch wide 



at the top, and a quarter inch at the bottom. Make as many 

 of them as there are slots in your wheel, and put one in 

 each slot. After they are securely fastened, bend each one 



slightly to form a cup as 

 shown at D in the illustra- 

 tion. Bore a hole through the 

 center of the wheel and place 

 an axle of round wood in it. 

 Fill the flask about half full 

 of water and after inserting 

 the stopper place it over a 



\ / &~j flame and allow the Water to 



JX ^ boil until a strong jet of 



steam comes from the tube. 



FIG. 266 



FIG. 267 



Mount your turbine so that 



the jet just touches the cups sho\vn in Figure 266. Write 

 a summary of how this experiment, performed on a large 

 scale, might be used in doing useful work. 



Experiment 113. How may the energy of falling water 

 be harnessed? 



Using the same turbine which you constructed for the 

 previous experiment, suggest and try out methods to il- 



1 See workbook, p. 59. 



lustrate each of the types of water wheels shown in Fig- 

 ure 279. Record your methods and results. 



Experiment 114. How is the energy of steam har- 

 nessed by the steam engine? 



This investigation will require reading from the refer- 

 ences to answer the questions. Study Figure 268 carefully. 



FIG. 268 



All parts of the steam boiler and engine are shown. Be sure 

 that you can tell what each part does, in the transformation 

 of the heat energy of the coal to the mechanical energy of 

 the flywheel, before attempting the exercises. 



In your notebook complete the statements. 



The steam engine transforms energy into 



energy. Four purposes for which steam engines are used 

 are . 



Steam is generated from water by the heat energy re- 

 leased by the _ of the fuel under the The steam 



first enters the engine in the , which is marked by the 



letter in the diagram. The moves back and forth 



in the cylinder, being pushed by the of the steam. 



Steam gets into the cylinder through openings marked 



and in the diagram. When one of them is admitting 



steam to the cylinder the other is connected with the , 



allowing the used steam to , The opening and closing 



of these ports or openings into the cylinder is controlled by 

 the valve marked in the diagram. The flywheel is 



shown at 



in the illustration. 



Experiment 115. How is the energy of gas and oil 

 harnessed? 



Secure a can of about a gallon capacity, with a tight 

 fitting lid. A smaller size will work. Make a hole in the side 

 and insert an old spark plug taken from an automobile. 

 Secure a spark coil and connect it with three dry cells and 

 a switch, as shown in the illustration. Attach the high ten- 

 sion or secondary wires as shown in the illustration, one to 



FIG. 269 



