162. State the laws connecting the vibration number with the length of a, rod, vibrating transversely—
1st. When the rod is fixed at both ends. 2nd. When it is fixed at one end only. 3rd. When it is free at both ends.
163. What partials may occur in each of the above cases ?
164. State what you know of the partials which may be produced by a tuning fork.
165. Give sketches showing the various ways in which a tuning fork may vibrate.
166. When the handle of a tuning fork is applied to a table, the fork's vibrations are communicated to the latter. Explain how this is effected. Account also for the louder sound thus produced.
167. How does change of temperature affect the pitch of a tuning fork ?
168. How can the velocity of sound in air be approximately ascertained, with no other apparatus than an open organ pipe giving C=518 ?
169. Given the velocity of sound in air, how can the velocity of sound in other gases be ascertained ?
170. Explain the methods by which the velocity of sound in solid bodies is ascertained.
171. A silver wire is stretched between two fixed points, and caused to vibrate longitudinally. Its length is varied till the tone it produces is in unison with a C1 fork (C'=512). It then measures 8ft. 4in. Calculate the velocity of sound in silver.
172. A copper rod 2ft. lOin. long is fixed in a vice at one end and rubbed longitudinally with a resined leather. The tone it emits is in unison with a C2 tuning fork (=1024). Find the velocity of sound in copper.
173. If a lath of metal 4ft. long, fixed at one end, vibrates laterally once a second; how many vibrations per second will it perform, when its length is reduced to 4in.?
174. How can the nodal lines of a vibrating plate or membrane be discovered ? Explain the principle of the method.
175. Describe by means of sketches two or three ways in which a square and a round plate may vibrate.
176. What are Combination Tones ? How many kinds of Combination Tones are there ? What are they respectively termed ?
177. How is the vibration number of a differential tone related to the vibration numbers of its generators ?
178. Describe some method of producing Differential Tones.
179. Calculate the Differentials produced by an Octave, Fifth, and Major and Minor Thirds.