Abstract
Abstract
Highlights
A prevailing myth is that water feels like concrete if one jumps onto it from a great enough height
Creating a cavity in front of an impacting object can be conducive to reducing its impact acceleration, as evident from figure 1(c)
After pinch-off the cavity divides into two parts, a pulsating air bubble attached to the downwards moving sphere and the upper bowl shaped distortion in the free surface retreating upwards creating a high-speed axisymmetric ‘Worthington’ jet (Worthington & Cole 1897; Gekle & Gordillo 2010), as seen in figure 2(a) from 92 to 115 ms
Summary
A prevailing myth is that water feels like concrete if one jumps onto it from a great enough height. One such example is shown, where a 50 mm sphere dropped from 0.72 m above the free surface results in an impulse with a peak impact acceleration of ∼8 g whereas the underwater acceleration is close to a constant value of ∼2 g (1c), indicating that at the moment of surface penetration the drag coefficient Cd is four times the steady state underwater free fall This initially high impact force is primarily due to the large rate of change of momentum of the added fluid mass (May 1975; Wang, Lugni & Faltinsen 2015; Wang, Faltinsen & Lugni 2019), which is the highest during a submergence depth of 10 %–20 % of the radius for spheres (figure 1a) (Shiffman & Spencer 1945; Moghisi & Squire 1981). Such a concept has been proposed in popular culture (e.g. Mythbusters, Hollywood movies), yet has not received careful scientific investigation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
