Billiards balls are made up of ‘thermoset resin’ which are words used to describe synthetic substances that set permanently in the shape that they are currently in when exposed to heat is an adjective used to describe synthetic substances that set permanently when heated. Another important part of physics believe it or not is the chalk (which actually contains no chalk at all!) that is rubbed onto the end of the cue which aids the player in their game due to friction applied allowing better control of the ball of the cue and less chance of slipping.
Application of Laws and Principles
In 8 ball you can describe the whole motion of the game with the aid of physics as well as a variety of laws related to physics. I will use the laws to describe each individual action of a play which will involve: the cue connecting the ball, the ball traveling across the table, the ball bouncing off of the cushioning and then finally hitting another ball into a pocket. When the ball connects with the cue there is a transfer of energy and momentum in which the Conservation of Energy law and Conservation of Momentum law apply, these laws state that energy and momentum are not lost or gained but are transferred to the object an its surroundings. The white ball is originally stationary on the table and the cue is rested between the players’ fingers (which act as a base for the shot), the player then proceeds to increase the momentum of the cue from stationary to an accelerating state. The cue carries its momentum on until it connects with the white ball causing the momentum to be transferred from the cue to the white ball, meaning that the white ball will travel at a speed close to that of the cue before the collision. Other laws that come into play in this demonstration are Newton's First Law, which says that an object will remain at rest until acted upon by an ‘unbalanced force’. In this case the cue is the ‘unbalanced force’ which makes the object act rest (the white ball) move from where it was. Newton’s Third Law tells us that for every action there is an equal but opposite reaction, this is shown in the above act because, the cue exerts a force on the ball to make it move and the ball places an equal force back on the cue to stop its momentum.
After the cue has collided with the white ball that ball must travel in a straight line along the felt table to get to the point that it was intended to reach. The ball cannot curve when it is on this path after being hit because the force has been sent through the ball at a particular angle and this is the direction that the ball travels in. The law applied in this particular part of the shot is the law of Conservation on Energy because even though the ball is slowly losing speed due to the external forces acting on the energy of the ball, the energy is still there it is just being moved to the table as it travels over its surface.
Seeing as the player has aimed the ball on an angle at the cushion to get around to his/her ball we must discuss what happens when the balls is in contact with and after the cushion. The ball is traveling towards to cushion at an angle and seeing as the ball is a completely solid object it isn’t going to deform at all when it hits the cushioning. The cushioning on the other hand will momentarily disfigure which will take some of the energy/speed away from the ball that has connected with it which means a transfer of energy has taken place between the ball and the cushion. The laws that apply to this action are the laws of Conservation of Energy, demonstrates by the point that even though the ball has lost energy, that energy has been absorbed by the cushion during the collision.
The final part of the actions that I have demonstrated is the action of the ball which has been moved by the cue, slowed down slightly by the friction of the table, lost energy due to bouncing off of the cushion, now into another ball pushing that ball into a pocket. The white ball is travelling toward another ball that is right in line to go in after the white ball collides with it. The white ball hits the other ball and exerts a force on it bringing into play a number of laws, the first being the Conservation of Energy law telling us that after the white ball has hit the coloured ball the white ball will lose the majority of its energy which will slow it down till it comes to a halt and the coloured ball will take off from a zero velocity to a velocity close to that of the white ball. The rest of the energy is lost in the form of sound energy, if we add the new energy of the coloured ball to the new energy of the white ball and make allowance for the energy lost to sound energy it shows that energy has been conserved throughout this action. Newton's 1st Law is demonstrated also because the coloured ball which was originally at rest has been acted upon by an unbalanced force (the white ball) and is now moving towards the pocket. Newton’s 2nd Law is also demonstrated by the collision between the balls (2nd Law is F = m x a) meaning that the force experienced by the coloured ball is due to the mass of the white all multiplied by the velocity that it is travelling at divided by the time it has taken to get there. Newton's 3rd Law tells us that every action has an equal but opposite reaction, demonstrating that as the white ball exerts a force onto the coloured ball it receives a force back to neutralise its initial force and direction that it is travelling.
Discussion of External Influences
The external influences that act during a game of 8 Ball are quite limited seeing as the game is generally played inside, the balls rarely travel in the air (if they do it is not for more than second). The external forces that act on the game of 8 Ball are forces of gravitational acceleration, friction and deformation. Gravitational acceleration acts on every ball on the table because when the balls collide or start to move, as they move gravitational acceleration and friction act on with the mass of the ball to cause the acceleration to become a deceleration and eventually cause the ball to stop. Deformation coupled with gravitational acceleration and friction cause the ball to slow down even faster than without the deformation. The deformation does not however take place on the ball itself, rather the cushioning that it inevitably will hit sometime during the game. When the cushion deforms it takes energy away from the ball and when it reforms it gives the ball a slight spurt of speed which quickly turns into a gradual deceleration.
Manufacture & Design
The manufacture and design of cues are generally limited; a cue is designed as a thin, cylindrical shape which tapers to about the size of a five cent piece as we get towards the end that the ball is hit with. The cue can be different by the way that it can have a hollowed inside (giving less power) or a fuller inside containing a rubbery type of material which provides extra power from the cue. The cue balls I have described in the materials section and these cannot be changed with the exception of a slight variation of weight found in each of the balls which cannot be controlled to a precise amount. The chalk that is rubbed onto the cue tip is now actually not made of half at all, rather is contains frictional particles for the extra control. The cue tips can make a difference to the game, if the cue tip is too hard and too flat the ball will not travel the top speed that it could and will send a vibration back down the cue making it hard to control. If the cue tip is too round the player will find themselves miscuing the ball a lot, meaning it will come off the side of the cue and travel in an undesired direction. If the cue tip is too soft it will absorb too much power from the white ball and can be easily dented and wrecked as well as affecting the accuracy of the players shots. The table is a vital part of the game because it is the surface where you play the game, it’s like playing on a bad sports ground. If the table becomes warn in the cushions the game is hard to judge, if the table gets chips on the playing surface the ball may take unwanted turns and this can get very frustrating. The cue is designed the way it is so it has very little resistance from the air and gravity acting on it while it is travelling towards the white ball. These are the reasons why the cue is light and tapered towards the front; the balls are obviously circular so they can roll around the table easily.
Conclusion
In the sport of 8 Ball Newton’s Law as well as the Conservation of Energy and Conservation of Momentum Laws are in use nearly everytime you have a shot which I actually found surprising. There are many differences in ideas to do with physics and billiards ranging from people that try and work out the effects of different types of felt to different cue tips. The external influences don’t really play that big part in physics as it is more the collisions between the balls that slows them down, the main external influence was the cushioning which slows the ball a little. Air shots are not really used in pool as it is not good for the cue tip, dangerous to the table and very difficult to control, but there are many techniques and strategies used by pool players proving that 8 Ball is also a game of strategy as well as aim.
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