Connecting Dynamics/Kinetics To Rugby
The study of dynamics/kinetics is another physics topic that can be related to the sport of rugby. The study of kinetics is a branch of classical mechanics that describes the motion of points, objects or groups of objects while considering the causes of motion. Newtons laws take a huge part in what occurs on a rugby field and being that it is a high contact sport there may be no better place to test and visualize these laws in action. The two rugby topics being focused on in this section are scrumming and tackling.
The Tackle
Tackling is probably the most important part of a rugby match. When a player is being tackled he is being hit with an extreme amount of force causing him to get pushed wherever the tackler pleases. We can apply the forces made in a tackle to newtons laws also. We will calculate how much force is generally put into a rugby tackle.
Sonny Bill Williams is a professional rugby player who plays for the New Zealand All Blacks. When he moves into a tackle he is accelerating at 2.54 m/s2. He also weighs 108 kg. We will use this data when calculating the net force made in a tackle.
Net Force: The net force put into a tackle is 272 Newtons.
Fnet = ? Fnet = ma
m = 108 kg Fnet = (108)(2.54)
a = 2.54 m/s2 Fnet = 274 N
Tackling is probably the most important part of a rugby match. When a player is being tackled he is being hit with an extreme amount of force causing him to get pushed wherever the tackler pleases. We can apply the forces made in a tackle to newtons laws also. We will calculate how much force is generally put into a rugby tackle.
Sonny Bill Williams is a professional rugby player who plays for the New Zealand All Blacks. When he moves into a tackle he is accelerating at 2.54 m/s2. He also weighs 108 kg. We will use this data when calculating the net force made in a tackle.
Net Force: The net force put into a tackle is 272 Newtons.
Fnet = ? Fnet = ma
m = 108 kg Fnet = (108)(2.54)
a = 2.54 m/s2 Fnet = 274 N
The Scrum
In rugby, a scrum is one of the ways you start the flow of play. It is when all the forwards on both teams battle for the ball with a single push. The amount of force being put into a scrum is incredible! Think of eight big strong athletes putting all their momentum into a single hit, that can compare to the force of 3 rushing bulls. We are going to calculate how much force is being put into a single scrum.
They say that the speed at which the two packs in a scrum collide can be matched to a rugby player running into a tackle. The average acceleration at which a rugby player moves into a tackle is 2.54 m/s2. We will use this in our calculations. In the professional league the average pack of forwards can produce up to 6000 lbs (2721 kg) of force into a single scrum. We will use this data when calculating the net force produced in a scrum.
Net Force: The average net force applied in a scrum is nearly 7000 Newtons of force!! That's a ridiculous amount!!
Fnet = ? Fnet = ma
a = 2.54 m/s2 Fnet = (2721)(2.54)
m = 2721 kg Fnet = 6911 N
According to newton's third law, for every force there is a reaction force that is equal in magnitude but opposite in direction. This means that if a pack of forwards can apply 6000 lbs of force into another pack, the reaction force will also be 6000 lbs.
In rugby, a scrum is one of the ways you start the flow of play. It is when all the forwards on both teams battle for the ball with a single push. The amount of force being put into a scrum is incredible! Think of eight big strong athletes putting all their momentum into a single hit, that can compare to the force of 3 rushing bulls. We are going to calculate how much force is being put into a single scrum.
They say that the speed at which the two packs in a scrum collide can be matched to a rugby player running into a tackle. The average acceleration at which a rugby player moves into a tackle is 2.54 m/s2. We will use this in our calculations. In the professional league the average pack of forwards can produce up to 6000 lbs (2721 kg) of force into a single scrum. We will use this data when calculating the net force produced in a scrum.
Net Force: The average net force applied in a scrum is nearly 7000 Newtons of force!! That's a ridiculous amount!!
Fnet = ? Fnet = ma
a = 2.54 m/s2 Fnet = (2721)(2.54)
m = 2721 kg Fnet = 6911 N
According to newton's third law, for every force there is a reaction force that is equal in magnitude but opposite in direction. This means that if a pack of forwards can apply 6000 lbs of force into another pack, the reaction force will also be 6000 lbs.