Suarez handball

[gwnn]

hotShot, just wondering, is there a good reason why in these sorts of comparative tables they use the kinetic energy instead of momentum? For me it's unclear which is most representative to the pain caused. :P I mean one is force*distance, the other one is force*time.

[kfay]

hotShot, just wondering, is there a good reason why in these sorts of comparative tables they use the kinetic energy instead of momentum? For me it's unclear which is most representative to the pain caused. :P I mean one is force*distance, the other one is force*time.

Furthermore, why aren't we taking into account size and hardness?

 

Sure a baseball has less energy, but it impacts you on a much smaller area of your body --> greater pressure.

 

Also, it is not inflatable, nor as pliable. So the impulse is much greater as well.

[hotShot]

hotShot, just wondering, is there a good reason why in these sorts of comparative tables they use the kinetic energy instead of momentum? For me it's unclear which is most representative to the pain caused. :P I mean one is force*distance, the other one is force*time.

My physics professor, made someone shot a bullet into a beer can filled with water.

(For the joy of one student he needed a volunteer to get rid of the beer first...)

The can was ripped to pieces and he explained that the water did not have enough time move out of the way so it had to absorb most of the energy. And that energy was used to deform the can.

 

I guess when a projectile hits your face the deformation has to correlate with the energy transfered.

 

But feel free to ask someone who is more competent in physics than me.....

[hotShot]

hotShot, just wondering, is there a good reason why in these sorts of comparative tables they use the kinetic energy instead of momentum? For me it's unclear which is most representative to the pain caused.  :P I mean one is force*distance, the other one is force*time.

Furthermore, why aren't we taking into account size and hardness?

 

Sure a baseball has less energy, but it impacts you on a much smaller area of your body --> greater pressure.

 

Also, it is not inflatable, nor as pliable. So the impulse is much greater as well.

You are right these are also factors to determine the damage.

 

Although I would have liked to find data to compare a soccer ball to a boxing glove.

[matmat]

hotShot, just wondering, is there a good reason why in these sorts of comparative tables they use the kinetic energy instead of momentum? For me it's unclear which is most representative to the pain caused.  :P I mean one is force*distance, the other one is force*time.

My physics professor, made someone shot a bullet into a beer can filled with water.

(For the joy of one student he needed a volunteer to get rid of the beer first...)

The can was ripped to pieces and he explained that the water did not have enough time move out of the way so it had to absorb most of the energy. And that energy was used to deform the can.

 

I guess when a projectile hits your face the deformation has to correlate with the energy transfered.

 

But feel free to ask someone who is more competent in physics than me.....

Tell me, did you read the text or did you just look at the kinetic energy table?

 

he discusses projectile size and elasticity as factors that need to be included in thinking about damage to the body...

 

gwnn and kfay are onto something...

 

if a 200lb (~100kg) man jogs into you at a normal pace of 5mi/h (8km/h), the kinetic energy you just experienced is 250J of energy (whatever the hell that means)... do you think that will do as much damage as a hockey puck launched at 100mph at your skull?

[Gerben42]

A penalty kick and a red card seems an insufficient penalty to pay for a deliberate handball that stopped a certain goal.

 

Having said that if that is the rule then the player must weigh up the risk and reward. So it is hard to criticize his actions on that basis.

 

I think the rule is a bad rule so my criticism go with the rule makers.

 

Funny, a commentator meant that when the goalie fouled a player who was just about to shoot on the goal, the penalty kick should be enough penalty and a red card for the goalie was over-the-top. The same penalty, but perhaps two different situations?

 

But I agree one should be able to give a penalty goal in cases like this.

[Cascade]

For example you score a penalty but your team mates run in the 16 before you shoot: you have to retake the penalty. Teammates running in the 16 is irrelevant to the fact that you beat the goal keeper. However, if you'd miss the penalty and your team mates score the rebound, the goal shouldn't count.

Disagree.

 

A penalty is a one on one event. The fact that half a dozen other guys are running at the goal keeper changes the dynamic and at the very least could cause a distraction.

[Cascade]

A penalty kick and a red card seems an insufficient penalty to pay for a deliberate handball that stopped a certain goal.

 

Having said that if that is the rule then the player must weigh up the risk and reward. So it is hard to criticize his actions on that basis.

 

I think the rule is a bad rule so my critcism go with the rule makers.

yes I think the rule should be sufficiently harsh that the players not only see no advantage to doing it but a significant disadvantage....IMO a penalty like automatic goal score seems to fit my definition.

In bridge terms this is not a penalty this is merely restoring equity when the goal was imminent.

[hotShot]

he discusses projectile size and elasticity as factors that need to be included in thinking about damage to the body...

Yes he did, but I did not.

 

I illustrated that it is a good idea, and legal by the rules of soccer, to protect yourself using your hand.

 

And I suggested that the rules tries to compensate for the fact that no referee can always make the right decision in such a situation.

 

Later I tried to give an example why energy and not momentum is used.

I hope that it was conclusive.

[matmat]

duplicate...

[matmat]

Later I tried to give an example why energy and not momentum is used.

I hope that it was conclusive.

not really... in fact, not at all.

 

you are trying to compare an incompressible fluid (water) inside a rigid container with a compressible fluid (air) inside an elastic shell.

[hotShot]

Later I tried to give an example why energy and not momentum is used.

I hope that it was conclusive.

not really... in fact, not at all.

 

you are trying to compare an incompressible fluid (water) inside a rigid container with a compressible fluid (air) inside an elastic shell.

Damn, it was such a memorable lecture.

[Fluffy]

talking about breaking rules, I don't understand why if there are players worth 100 million € there aren't people willing to bounty on them so that if a substitute player in his thirties breaks his knee into tiny pieces so he's got to retire forever he gets some millions reward.

[gwnn]

he discusses projectile size and elasticity as factors that need to be included in thinking about damage to the body...

Yes he did, but I did not.

 

I illustrated that it is a good idea, and legal by the rules of soccer, to protect yourself using your hand.

 

And I suggested that the rules tries to compensate for the fact that no referee can always make the right decision in such a situation.

 

Later I tried to give an example why energy and not momentum is used.

I hope that it was conclusive.

Sorry but it just sounds to me like "because your physics professor said so, it's true." I don't see any way in which he explained his reasoning. What would happen if someone had just said:

 

The can was ripped to pieces and he explained that the water did not have enough time move out of the way so it had to absorb most of the energy momentum. And that energy momentum was used to deform the can.

[hotShot]

Sorry but it just sounds to me like "because your physics professor said so, it's true." I don't see any way in which he explained his reasoning. What would happen if someone had just said:

 

The can was ripped to pieces and he explained that the water did not have enough time move out of the way so it had to absorb most of the energy momentum. And that energy momentum was used to deform the can.

Don't expect more physics from me, didn't you read I tried to compare an incompressible fluid (water) inside a container (human body) with a compressible fluid (air) inside an elastic shell (ball).

[Phil]

Isn't a game misconduct accompanied by a suspension for the next game?

NHL Rules

 

I asked a NHL junkie and double checked it against the NHL site.

 

Refs cannot impose a misconduct penalty against a player for the next game. The film is sent to Toronto who makes the decision on a suspension.

[Free]

Games like icehockey and American Football are very used to a lot of breaks. So it is easy to use the breaks for a video challenge. Football is different. The rules try to make the game as fluent as possible. Video challenge have a lot of disadvantages besides their obvious advantages, so they are seldom the solution. (of course they had been in the 1/8 finals...)

It's true that other sports are used to a lot of breaks. That's why I propose NOT to use challenges, but to let the 4th ref reconsider based on video footage. This doesn't stop the game, in the contrary: players don't have to protest against a doubtful decision because video footage will be used to confirm/modify the made decision.

 

Not sure about this, but I think the 4th ref doesn't have a full time job...

[G_R__E_G]

Isn't a game misconduct accompanied by a suspension for the next game?

NHL Rules

 

I asked a NHL junkie and double checked it against the NHL site.

 

Refs cannot impose a misconduct penalty against a player for the next game. The film is sent to Toronto who makes the decision on a suspension.

That is correct and further to that it's probably only about 5% of game misconducts that result in further suspensions in the NHL.

[gwnn]

The proposition I read somewhere was to let the coaches have 2 chances each to 'challenge', regardless of the success of the challenges. Sounds sensible to me. Anyway offside could also be done electronically, by putting chips in the players. Yes yes sign of the beast and end days ;)

 

Looks to me that there are four important types of decisions that are routinely gotten wrong:

-offsides

-penalties (i.e. fouls in the penalty area)

-off the ball offences (for red cards)

-goals i.e. has the ball gone in?

 

I think the fourth is the least common major mistake and the last decision like this that I remember before 2010 was Roy Carroll's very funny blunder about three years ago:

 

It is very characteristic of FIFA that they are thinking of introducing technology to probably the least prevalent refereeing problem.

[pooltuna]

The proposition I read somewhere was to let the coaches have 2 chances each to 'challenge', regardless of the success of the challenges. Sounds sensible to me. Anyway offside could also be done electronically, by putting chips in the players. Yes yes sign of the beast and end days ;)

 

Looks to me that there are four important types of decisions that are routinely gotten wrong:

-offsides

-penalties (i.e. fouls in the penalty area)

-off the ball offences (for red cards)

-goals i.e. has the ball gone in?

 

I think the fourth is the least common major mistake and the last decision like this that I remember before 2010 was Roy Carroll's very funny blunder about three years ago:

 

It is very characteristic of FIFA that they are thinking of introducing technology to probably the least prevalent refereeing problem.

Stay away from 666 and just use wrist/ankle bands ;)

[jjbrr]

FIFA are a bunch of knuckle-dragging droolers for not implementing video replays for the refs imo.

[MickyB]

Goal wrongly given

[gwnn]

oh yea that was a funny one haha

[Tomi2]

 

this is better!

 

Bayern München vs FC Nürnberg, with this goal Bayern won 1-0

 

Nürnberg, needing every point to avoid beein relegated, protested, and for some unbelievable reasons German Footabal Federation overruled the decision and made the teams replay the match. This decision was not covered by the rules that say "once a decision has been finally made by the referee, it can not be overruled anymore by outstanding authorities"

[reminds me of that England-Sweden case in Belgium]

 

funny thing is Bayern won 5-1 in the rematch and Nürnberg got relegated because of their bad goal difference

[gwnn]

But when was this? Do you agree that goal line decisions are a rarer problem than the other three I mentioned?