Suction-ejection of a ping-pong ball in a falling water-filled cup

Emergent Scientist

卷:6

Malhomme N.¹  Barlet A.¹ 

[1] Magistère de physique d’Orsay, Université Paris-Saclay;

关键词: capillary suction;    surface tension;    free fall;    buoyancy;   

DOI  :  10.1051/emsci/2022002

来源: DOAJ

【 摘 要 】

Dropping a water-filled cup with a ping-pong ball inside to the ground expels the ball much higher than its initial height. During free fall, the absence of gravity in the reference frame of the cup makes capillary forces dominant, causing the ball to be sucked into water. At impact, the high velocity ejection is due to the strong Archimedes’ force caused by vertical acceleration. In this paper, we study the dynamics of the capillary sinking of the ball during free fall and the ejection speed at impact, using tracking and high-speed imaging. In particular, we show that at short-time, the sinking is governed by capillary and added mass forces.

【 授权许可】

Unknown