A microscopic modeling of the instant coffee effect

2nd International Conference on Mathematical Modeling in Physical Sciences 2013

物理学;数学

Isoda, M.^1 ; Nishimori, Y.^1

Department of Physics, Faculty of Education, Kagawa University, Saiwai-cho 1-1, Takamatsu 760-8522, Japan^1

关键词: Air mass;    Coupled oscillators;    Eigen frequencies;    Hot water;    Microscopic modeling;    Physics education;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/490/1/012030/pdf
DOI  :  10.1088/1742-6596/490/1/012030

来源: IOP

【 摘 要 】

So-called the instant coffee effect is well known in the field of the physics education. The effect is explained that the sound yielded by touching the cup with a spoon is shifted to low-pitched by adulterating bubble owing to putting a spoon of instant coffee into hot water. The phenomenon has been interpreted with the averaged density and compressibility of the fluid in the macroscopic relation for the sound velocity, v = √(kp)-1. We introduce the linear coupled oscillator model with finite oscillators including the impurity air-mass oscillator. The model may well reproduce the increase in the shift of the eigen frequency accompanying with the amount of bubble.