A - A metal rod is held in the finger and thumg near one end - the rod in a vertical line. With a hammer we strike one end of the rod. As the position of the holding changes the pitch emitted by the bar changes. We are exciting the bar compress!onaIly - longitudinally. What it emits is governed by many things: its stuff - its geometry -where it is held. For certain positions of "damping" the bar has enormous acoustic life and very very high Q. By the Q of a system we mean - in a general way - how much energy it returns for the energy we give it. At certain positions this bar gives rise to fantastically high-pitched emission.

B - We have an array of metal plates - of different stuff - of different shape. These are called CHLADNI PLATES. They are fixed at the center to a pin rigidly bound to the plate. We bow the plate with a violin bow. It sounds. It is vibrating. But HOW? It is too fast to see. So we sprinkle it with sand or with sugar and low and behold - a WONDROUS thing arises: The sand takes up beautiful patterns - governed by how we bow the plate - where we bow the plate and so on. The beautiful figures resulting are called CHLADNI FIGURES.

C - It is rather well known that glasses and goblets can be stroked -
excited - bu rubbin a wet finger along the edge. If now we arrange a set of these - say eight - tuned with different levels of water - a delightful music can be played. And here again we have relaxation oscillations - the finger grips the edge of the glass - I ets go - and this action is repeated.

D - So too a steel drum can be shaped with a hammer - giving different shaped segments - of different size - of different thickness. The music which these emit is indeed delightful.

E - A tuning fork - say 512 vps - one octave above middle C - is struck. You hear 512 vps. Now if this fork is moved toward a distant hearer and then away from the hearer a change in pitch is noted. This is called the Doppler Effect. It plays a role in both light and in sound since it is a consequence of more waves or less waves reaching the observer per unit time. You detect this when you hear a Police siren! I

1. The Idea of the Center of Gravity
2. Newton's First Law of Motion: Inertia
3. Newton's Second Law of Motion: The Elevator Problem
4. Newton's Third Law of Motion: Momentum
5. Energy and Momentum
6. Concerning Falling Bodies & Projectiles
7. The Simple Pendulum and Other Oscillating Things
8. Adventures with Bernoulli: Bernoulli's Principle
9. Soap Bubbles and Soap Films
10. Atmospheric Pressure
11. Centrifugal Force and Other Strange Matters
12. The Strange Behavior of Rolling Things
13. Archimedes' Principle
14. Pascal's Principle: The Properties of Liquids
15. Levers, Inclines Planes, Geared-wheels and Other Machines
16. The Ideas of Heat and Temperature
17. Thermometric Properties and Processes
18. How to Produce Heat Energy
19. Thermal Expansion of Stuff: Solids
20. Thermal Expansion of Stuff: Gases & Liquids
21. The Strange Thermal Behavior of Ice and Water
22. Heat Energy Transfer by Conduction
23. Heat Energy Transfer by Convection
24. Heat Energy Transfer by Radiation
25. Evaporation, Boiling, Freezing: A Dramatic Adventure
26. Miscellaneous Adventures in Heat
27. The Drama in Real Cold Stuff: Liquid Nitrogen
28. The Physics of Toys: Mechanical
29. The Physics of Toys: Acoustic and Thermal
30. Waves: Kinds of Properties
31. Sound Waves: Sources of Sound & Pitch and Frequency
32. Vibrating Bars and Strings: The Phenomenon of Beats
33. Resonance: Forced Vibrations
34. Sounding Pipes
35. Vibrating Rods and Plates
36. Miscellaneous Adventures in Sound
37. Electrostatic Phenomena: Foundations of Electricity
38. Electrostatic Toys, Part 1
39. Electrostatic Toys, Part 2
40. Adventures with Electric Charges
41. Adventures in Magnetism
42. Ways to "Produce" Electricity
43. Properties and Effects of Electric Currents
44. Adventures in Electromagnetism
45. Further Adventures in Electromagnetism
46. Miscellaneous and Wondrous Things in E&M

Demonstrations in Physics was an educational science series produced in Australia by ABC Television in 1969. The series was hosted by American scientist Julius Sumner Miller, who demonstrated experiments involving various disciplines in the world of physics. The series was also released in the United States under the title Science Demonstrations.

This program was a series of 45 shows (approximately 15 minutes each) on various topics in physics, organized into 3 units: Mechanics; Heat and Temperature / Toys; and Waves and Sound / Electricity and Magnetism.