Here are some possible 5-minute topics for your second-week presentations:
| # | question |
|---|---|
| 1 | Just before they burst, soap bubbles lose their color and become very transparent. Why? |
| 2 | The flame of a candle or a match is of colors that vary from the bottom to the top of the flame. Why? Natalie has claimed this one. |
| 3 | Why does our smoke detector go off just before a lightning strike? |
| 4 | You stand on a bathroom scale and read your weight. If the air were pumped out of the room, would the scale's reading change? |
| 5 | How tall a drinking straw can you use? Does it matter if it's twisted? (Mike has claimed this question.) |
| 6 | I can get one set of notes out of the headpiece of a flute (this is a cylinder with a hole you blow into/over, and the other end open.) normally, but if I close off the other end, I get another set of notes. How are they different, and why? |
| 7 | Estimate the Fermi energy of copper. |
| 8 | Can one photon turn into an electron-positron pair? |
| 9 | What is the point of a throwing stick, or atlatl? Daniel has this one. |
| 10 | We have two chimes, one that vibrates at 440 Hz and one at 441 Hz. If you put them near each other and whack one of them, of course it chimes; if you stop it, you can hear the other one ringing, too. Strangely, if you whack and stop, sometimes the other chime is barely vibrating, sometimes it's got a pretty good amplitude, although never as strong as the whacked chime. Explain all this. |
| 11 | Explain the phase lag between tides and the moon's position. (Joe?) |
| 12 | Alice is doing rainbows. |
| 13 | Charles is going to tell us why different planets have different atmospheric pressures. |