KINEMATICS
Kinematics are very apparent in Rugby. It can be seen through players running
with the ball, running without the ball and even through players kicking the
ball. In this section I will talk about Maximum speed, acceleration and
projectile motion in Rugby and explain how they work and why they are
important.
with the ball, running without the ball and even through players kicking the
ball. In this section I will talk about Maximum speed, acceleration and
projectile motion in Rugby and explain how they work and why they are
important.
Maximum speed
In rugby, it is important to be fast. The faster the player is the harder it will be to hit them, which is why it is important for players to be as close to maximum speed as possible when they are running with the ball. But how do players reach maximum speed, and how long does it take to get there?
On average it takes an athlete about 2.5-3 seconds to reach their maximum speed. This means that they have to accelerate as fast as possible for that time, and then after 3 seconds continue to run at that speed in order to maintain it. I calculated my maximum speed through timing myself running 100m. I found that my maximum speed was 10.15 m/s, and it took me 2.5 seconds to reach that speed (see calculations). This information shows that on the rugby pitch, I would need aproximately 2.5 seconds to reach my ideal maximum speed while running with the ball. A tactic used in Rugby to hit maximum speed with the ball faster is to start running without the ball, and by the time you are close to running at your maximum speed, your teammate passes you the ball an you are already running with momentum close to your full speed.
Acceleration
As mentioned before, it is important to be able to run at your maimum speed as a rugby player. In order to do that, players need to be able to accelerate very quickly. Acceleration takes place in the time that it takes to reach maximum speed. Not all players will accelerate at the same speed. Factors that affect rate of acceleration are; players weight, players leg strength, type of shoe, etc. One of the fastest rugby players in the world; Bryan Habana ran the 100m in 10.4 seconds. Assuming it took him about 2.25 seconds to reach maximum speed, his acceleration would have been 4.39 m/s^2. Compare that to my acceleration of 4.06 m/s^2 and its clear that he would blow by me on the rugby pitch. Shoes also have an impact on how fast players can accelerate. Faster player wear lighter shoes with rubber studs on the bottom to improve their speed at which they run, where as bigge players wear heavier shoes with metal studs at the bottom because acceleration isnt as important as strength and power for them. At the end of the day, being able to accelerate quickly in rugby is one of the most important things. If you can get to your maximum speed before your oponent, it could be the difference between scoring the tri or getting tackled, and that is why acceleration is so key for rugby players.
As mentioned before, it is important to be able to run at your maimum speed as a rugby player. In order to do that, players need to be able to accelerate very quickly. Acceleration takes place in the time that it takes to reach maximum speed. Not all players will accelerate at the same speed. Factors that affect rate of acceleration are; players weight, players leg strength, type of shoe, etc. One of the fastest rugby players in the world; Bryan Habana ran the 100m in 10.4 seconds. Assuming it took him about 2.25 seconds to reach maximum speed, his acceleration would have been 4.39 m/s^2. Compare that to my acceleration of 4.06 m/s^2 and its clear that he would blow by me on the rugby pitch. Shoes also have an impact on how fast players can accelerate. Faster player wear lighter shoes with rubber studs on the bottom to improve their speed at which they run, where as bigge players wear heavier shoes with metal studs at the bottom because acceleration isnt as important as strength and power for them. At the end of the day, being able to accelerate quickly in rugby is one of the most important things. If you can get to your maximum speed before your oponent, it could be the difference between scoring the tri or getting tackled, and that is why acceleration is so key for rugby players.
Bryan Habana scoring a try through accelerating with the ball
Projectile Motion
In rugby projectile motion can be seen every game. From the kick off to passing the ball to kicking conversions, there is clearly a variety of scenarios where projectile motion is present. First off, when a rugby player is kicking the rugby ball, it can not be kicked accurately in just any random way. The most accurate way to kick the ball is to have it spinning backwards while in motion in the air, this has to be taken into consideration among other things when kicking the ball. Another worry should be that the other team can block your kick, so you must not take your sweet time to kick. It must be a fast and powerful process in order for it to be successful. Lets look into the basic stats of a successful kick; The kick must be at an angle around 35-45 degrees or higher in order for it to even be on course to go through the post. On top of that, you have to pick with enough force for the ball to travel enough distance and also for the ball to get high enough to not miss the posts. When testing a kick through the post, i found that a succesful kick took about 1.6 seconds to get through the posts. When taking into consideration the other team attempting to block your kick, you must also make sure your kick is quick and to the point, or it will get blocked. here are some calculations of an ideal drop goal in rugby :
Projectile Motion
In rugby projectile motion can be seen every game. From the kick off to passing the ball to kicking conversions, there is clearly a variety of scenarios where projectile motion is present. First off, when a rugby player is kicking the rugby ball, it can not be kicked accurately in just any random way. The most accurate way to kick the ball is to have it spinning backwards while in motion in the air, this has to be taken into consideration among other things when kicking the ball. Another worry should be that the other team can block your kick, so you must not take your sweet time to kick. It must be a fast and powerful process in order for it to be successful. Lets look into the basic stats of a successful kick; The kick must be at an angle around 35-45 degrees or higher in order for it to even be on course to go through the post. On top of that, you have to pick with enough force for the ball to travel enough distance and also for the ball to get high enough to not miss the posts. When testing a kick through the post, i found that a succesful kick took about 1.6 seconds to get through the posts. When taking into consideration the other team attempting to block your kick, you must also make sure your kick is quick and to the point, or it will get blocked. here are some calculations of an ideal drop goal in rugby :
Video of drop goal trial.