@jaspritb1 can bowl at speeds of around 145 kmph coupled with a rotational speed of 1000 RPM and a very stable seam position. This gives a spin ratio of nearly 0.1 for the cricket ball. Experiments on a rotating sphere at the National Wind Tunnel Facility, @iit.kanpur conducted by this writer and his students, have revealed that this spin ratio puts the ball into the reverse Magnus effect regime. A downward force on a cricket ball moving at Bumrah’s pace causes it to dip very sharply and therefore batsmen find it difficult to pick his deliveries. #Bumrah can consistently bowl at speeds in excess of 145 kmph which makes him one of the quickest bowlers in world cricket at the moment. In addition, his unconventional high-arm action has proved extremely difficult for batsmen to read. The direction of the Magnus force is dependent on a parameter known as spin ratio. It is the ratio of the tip speed of the ball due to rotation (equal to the ball’s angular speed multiplied by its radius) to its linear speed (delivery speed in common terminology). The reverse Magnus force on a cricket ball moving with backspin has the effect of making the ball dip quicker. A dipping ball moving at great pace makes it extremely difficult for batsmen to judge its trajectory and hit it. In fact, it is a wicket-taking ball. (Sanjay Mittal is Professor, Aerospace Engineering, at IIT Kanpur) #cwc2019 #cwc19india #icc @indiancricketteam #virat #msdians #ms #mumbaiindians @mumbaiindians @icc #followyourgame #thisiswhyweplay #icc2019 #worldcup2019🏆 #world #lit #score #wicket #saturday https://www.instagram.com/p/BxlvocNnISY/?igshid=1qcjnhdophjzt