The hot chocolate effect

Introducing bubbles into a cup with liquid changes the pitch of the sound it makes when tapped with a spoon. This is known as the hot chocolate effect. Simple experiments that can be performed at home, are presented, demonstrating the changing speed of sound in water when bubbles are present. A simplified but effective mathematical model is derived. In addition to demonstrating the effect, the experiments described provide an opportunity for students to develop skills to think like a scientist by devising and testing explanations.

Pojav vroče čokolade

Uvajanje mehurčkov v skodelico s tekočino spremeni višino tona, ki ga slišimo, ko skodelico udarimo z žlico. To je pojav vroče čokolade. Predstavljeni so enostavni poskusi, ki jih je mogoče izvesti doma in demonstrirajo spreminjanje hitrosti zvoka v vodi, ko so prisotni mehurčki. Izpeljan je enostaven a uporaben model. Opisani poskusi ponujajo priložnost za učence in dijake, da razvijajo sposobnost znanstvenega razmišljanja s predlaganjem in testiranjem razlag.