 # forces in badminton

The oscillating time of a shuttlecock can also be predicted by equation (1). Structures at the micro-scale are good precursors for small water droplets resulting from vapor condensation. Measurements of the frequency of different downward strokes during the last four Olympic finals. Another way to classify the different strokes consists in noting the direction: the up-going family is composed of clear and lift, while the down-going family includes smash, drop and kill (which is an offensive shot hit from the net area and not reported in figure 19). Figure 13 shows that increasing air flow reduces the cross-section S of the projectile by a factor 2 as the flow velocity increases from 0 m s−1 to 50 m s−1. On the other hand, the aerodynamic torque scales as \rho {{R}^{2}}{{U}^{2}}l. Gyroscopic stabilization only occurs if we have R\Omega /U\gg {{R}^{2}}\sqrt{\rho l/J}.

The Summation of Forces is a significant aspect in executing an optimal badminton smash shot and can be defined as “the sum of all forces, generated to … Figure 5. For similar initial conditions, the skirt deformability indeed induces a modified trajectory which is more triangular than the normal one.

The velocity of point B in the reference frame along the vectors {{{\bf e}}_{GB}} and {{{\bf e}}_{\varphi }} is given by: The velocity of point C along the vectors {{{\bf e}}_{GC}} and {{{\bf e}}_{\varphi }} is: Hence the angle satisfies the following equation: where {{M}_{B}}l_{GB}^{2}+{{M}_{C}}l_{GC}^{2} is the moment of inertia of the shuttlecock along the z direction. It is practically not very easy to reduce the mass of a plastic projectile while keeping its robustness and price unchanged, which explains why the two masses are different. Find out more.

For clear strokes, the trajectory ends with a nearly vertical fall. For clears, drops and lifts, the frequency of non-winning shots is much larger than the frequency of killing shots, which emphasizes that these shots are defensive or preparatory shots; this contrasts with drives, smashes and net shots which largely dominate the statistics of killing shots. The probability of each family can be approached with geometrical considerations. http://www.ck12.org/physical-science/Types-of-Friction-in-Physical-Science/lesson/Types-of-Friction-MS-PS/, https://prezi.com/cdt-wki18aft/biomechanics-in-badminton/?webgl=0, https://phys.org/news/2015-06-physics-badminton.html, https://www.youtube.com/watch?v=vPPXn2vUlvk, https://www.youtube.com/watch?v=Y4B1SoFKnBo (THIS HELPED THE MOST), Created with images by annca - "badminton shuttle sport" â¢ moerschy - "badminton ball sport" â¢ PDPics - "badminton shuttlecock sports" â¢ alainalele - "badminton simple fÃ©minin" â¢ cometstarmoon - "Running Toward Giant Shuttlecock (1)" â¢ danxoneil - "Shuttlecocks @ Nelson-Atkins Museum of Art | Kansas City, MO" â¢ ianpatterson99 - "IMG_9390" â¢ MR MAO PICS - "160513-F-QG390-3542" â¢ Tabble - "badminton bat sport" â¢ alainalele - "BADMINTON" â¢ annca - "badminton shuttle sport".

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The first games important to the creation of badminton were practised in Asia 2500 yr BC [].Soldiers played ti-jian-zi, which consisted of exchanging with their feet a shuttle generally made of a heavy leather ball planted with feathers (figure 1(a)). This plot is obtained for a shuttlecock of aerodynamic length \mathcal{L}=4.6\;{\rm m}, initially launched at y = 2 m with an initial angle {{\theta }_{0}}=15{}^\circ. One deduces that a shuttlecock does several turns before stabilizing if the initial angular velocity verifies {{\dot{\varphi }}_{0}}\gtrsim U\sqrt{\rho S{{C}_{D}}/{{l}_{GC}}{{M}_{B}}}. In practice, players perform tricks called 'spin in' and 'spin out', which consist of gently hitting the shuttlecock and simultaneously gripping the cork to maximize the initial spin {{\dot{\varphi }}_{0}} positively or negatively.

Considering typical values (l\simeq 3\;{\rm cm}, R\simeq 3\;{\rm cm} and \rho =1.2\;{\rm kg}\;{{{\rm m}}^{-3}}), we deduce the following criterion for gyroscopic stabilization: R\Omega /U\gg 0.1. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.

Table 2.

In order to answer this question, shuttlecock prototypes have been constructed. Using the previous values for shuttlecock characteristics and the initial velocities in experiments shown in figures 3(a) and (b), we estimate the oscillating times using relation (4). (a) Side view of the court showing the different shuttlecock trajectories during a game . In order to pass over the net, downward strokes have to be hit from the striped area.

The purpose of this section is to understand this complex dynamics. The second one, denoted as {{\tau }_{o}}, is the pseudo-period of oscillations. Sketch of a feather showing its microstructure.

This image was made available on Wikipedia under a creative commons CC BY SA 3.0 licence. The determination of U0, {{\varphi }_{0}} and \dot{{{\varphi }_{0}}} for the experiments shown in figure 3(a) and (b) allows us to estimate the flipping time. Cooke recorded the trajectories of different shuttlecocks in the court and compared them to numerical simulations . This section quantitatively describes this effect shown in figure 15(a). These predictions are close to the experimental values of {{\tau }_{f\,{\rm exp} -a}}=16\;{\rm ms} and {{\tau }_{f\,{\rm exp} -b}}=39\;{\rm ms}. It works to advance physics research, application and education; and engages with policy makers and the public to develop awareness and understanding of physics. In order to understand the shuttlecock behavior after impact, it is necessary to evaluate the forces applied to it, namely weight and aerodynamic pressure forces. Figure B1. A lift (4) is actually an underarm clear played from around the net area. Figure 9(b) shows a chronophotograph of a prototype flipping during its fall in water. In order to understand the shuttlecock behavior after impact, it is necessary to evaluate the forces applied to it, namely weight and aerodynamic pressure forces. Figure 11. push and pull,muscular force gravitational force. The cork being denser than the skirt, a shuttlecock has distinct centers of mass and pressure, and thus undergoes a stabilizing aerodynamic torque setting its nose ahead. Numerical trajectories correspond to experimental ones and predict the range for both kinds of shuttlecock.

The maximal range xmax is calculated for the maximal velocity recorded in a badminton court, {{U}_{0}}=117\;{\rm m}\;{{{\rm s}}^{-1}}, and for the corresponding optimal initial angle {{\theta }^{\star }} which verifies (\partial {{x}_{0}}/\partial {{\theta }_{0}})({{U}_{{\rm max} }},{{\theta }^{\star }})=0. (a) Experimental flipping time {{\tau }_{f\,{\rm exp} }} as a function of the one {{\tau }_{f\,th}} predicted by equation (2). . You do not need to reset your password if you login via Athens or an Institutional login. Obayashi et al also investigated the effect of a shuttlecock rotation on to its skirt deflection . You will only need to do this once. Since 2008, all the finals of the Olympic Games and the World Championships have been contested by Lin Dan (China) and Lee Chong Wei (Malaysia). The initial launching conditions correspond to a high clear: {{U}_{0}}=26\;{\rm m}\;{{{\rm s}}^{-1}} and {{\theta }_{0}}=56{}^\circ. On the x-axis, one finds the flying time {{\tau }_{0}} divided by the time of reaction {{\tau }_{r}} of a player ({{\tau }_{r}} is about 1 s for trained players). We propose classifying badminton strokes in the diagram drawn in figure 19(b). At first glance, parameters in the aerodynamic length \mathcal{L} do not depend on hygrometry. The maximal range xmax is calculated for the maximal velocity recorded in a badminton court, {{U}_{0}}=117\;{\rm m}\;{{{\rm s}}^{-1}}, and the corresponding optimal initial angle {{\theta }^{\star }} which verifies (\partial {{x}_{0}}/\partial {{\theta }_{0}})({{U}_{{\rm max} }},{{\theta }^{\star }})=0. This leads to a high sensitivity of the badminton game to wind. In this section, we study how the flight of a shuttlecock depends on its characteristics (mass, composition and geometry) and on the fluid parameters (density, temperature and humidity). (a) Prototype of a shuttlecock made with a dense iron ball and a light plastic skirt. Badminton strategy consists of performing the appropriate shuttlecock trajectory, which passes over the net, falls in the limit of the court and minimizes time for the opponent reaction. The different characteristic times arising from (1) can finally be compared to the data. Plot of the experimental angle between the shuttlecock axis and its velocity as a function of the coordinate s of the shuttlecock along its trajectory divided by the curvilinear coordinate when the projectile reaches the floor (s={{s}_{{\rm max} }}).

The smash (6) is a fast ball with a sharp straight trajectory aimed either at the opponent's body or at the limits of the court. Forces exerted on each feather (as represented in figure 15(a) with blue arrows) create a torque which puts a projectile into rotation so that feathers rip through air. Thus the shuttlecock is always aligned with the velocity direction, corresponding to the trajectories studied in section 2. The rotational velocity Ω is measured as a function of the projectile speed U, as shown in figure 15(b). For each impact, the shuttlecock speed U and its oscillating time are measured. (b) Rotation velocity R\;\Omega as a function of the translation speed U for a plastic (blue dots) and a feathered shuttlecock (red squares). The skirt rigidity of a plastic shuttlecock is reduced by cutting it longitudinally (first image in figure 13). We thank F Gallaire for unlimited interest concerning this subject. We now discuss how the shuttlecock geometry influences its flipping dynamics, which ideally might explain why a shuttlecock opening angle Λ close to 45 °was selected (figure 2(c)). For other strokes, the stabilizing time is much shorter than the total flying time. Why don't libraries smell like bookstores? Figure 18.

(c) An example of a feathered shuttlecock.

A typical example of the time evolution of is plotted in figure 4. Wind tunnel measurements also reveal that there is no lift force on a shuttlecock when its axis of symmetry is aligned along the velocity direction.

For a standard impact, the two initial conditions given to a shuttlecock are thus not independent. Figure 20. (b) Experimental initial angular velocity {{\dot{\varphi }}_{0}} times the skirt length L, as a function of the shuttlecock initial velocity U after its impact with a racket. ). As a light and extended particle, it flies with a pure drag trajectory. Badminton players always test shuttlecocks before competitions.

A torque balance around G provides the following equation in the realistic limit S{{M}_{C}}\gg s{{M}_{B}}: where CD is the drag coefficient of a sphere and lGC the distance between the points G and C ({{l}_{GC}}={{M}_{B}}/{{M}_{C}}\;{{l}_{BC}}). The equation of motion for such a projectile is M\frac{d{\bf U}}{dt}=M{\bf g}-\frac{1}{2}\rho S{{C}_{D}}U{\bf U}. In the case of standard impacts, we saw in figure 6(b) that L{{\dot{\varphi }}_{0}}/U\sim 1. During vertical fall, wind blowing horizontally at a velocity Uw deviates the impacting point of the shuttlecock by a quantity U_{w}^{2}{{{\rm sin} }^{2}}{{\theta }_{0}}/g. +
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