Heat changes how a tuning fork vibrates, which shifts the pitch it produces. You chill a 640 Hz fork overnight in a freezer, then warm it in stages using a beaker of heated water on a stove. At each of five temperatures — 0, 25, 50, 75, and 100 degrees Celsius — you strike the fork and measure its frequency with a sound sensor and scope. The data shows a small but steady drop in frequency as the fork gets hotter.

Some thermal changes are too subtle to notice without precise instruments. A 640 Hz tuning fork reads 641.6 Hz at 0°C, but as it warms the frequency edges downward. By 100°C it has dropped to 639.9 Hz — less than 2 Hz across the full range. At each temperature, an infrared thermometer confirms the reading while a sound sensor and scope capture the frequency. The result shows that even small temperature changes alter how the metal vibrates.

Heat changes more than just temperature — it can also weaken a magnet's pulling power. You test five magnets at temperatures from 0°C to 100°C. At each temperature you press a magnet into a flat tray of steel washers and count how many stick. At 0°C the magnets grab around 30 washers. At 100°C they pick up fewer than 10. That steep drop shows how dramatically rising temperature reduces magnetic strength.