Getbig Bodybuilding, Figure and Fitness Forums
Getbig Main Boards => Gossip & Opinions => Topic started by: Coach is Back! on April 22, 2013, 09:41:23 AM
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I need help. I hate math (any kind of math) more than I hate waterfalls and spiders. That being said, I still have to my fair share of "math" when it comes to load percentages, etc. I know there are some academically smart people on here, wife's not here so I can't ask her. So here it goes.
If I have a 155lbs RB and he and a 270-290lbs LB run into each other, what would be the force of contact? Of course the RB would be going a longer distance (about 10 yard) and running at a much more explosive rate. Not even sure I asked the question properly, but this is what I came up with.
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I need help. I hate math (any kind of math) more than I hate waterfalls and spiders. That being said, I still have to my fair share of "math" when it comes to load percentages, etc. I know there are some academically smart people on here, wife's not here so I can't ask her. So here it goes.
If I have a 155lbs RB and he and a 270-290lbs LB run into each other, what would be the force of contact? Of course the RB would be going a longer distance (about 10 yard) and running at a much more explosive rate. Not even sure I asked the question properly, but this is what I came up with.
You would need to know the acceleration/speed to determine this.
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You would need to know the acceleration to determine this. F=ma Force=Mass*Acceleration
RB has a 1.7sec 10yrd split. Average OL has about a 1.9-2.0 split.
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In other words, a 155 lb person running at full speed could potentially generate more impact than a fat ass permabulker running 2 mph.
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RB has a 1.7sec 10yrd split. Average OL has about a 1.9-2.0 split.
How fast were they going at the point of impact though? That is what matters.
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In other words, a 155 lb person running at full speed could potentially generate more impact than a fat ass permabulker running 2 mph.
Yes.
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How fast were they going at the point of impact though? That is what matters.
Hard to say. We measure in time not MPH.
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Coach has a good heart.
But God Damn! He is a slow mother fucker!
No offense.
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How fast were they going at the point of impact though? That is what matters.
speed= distance/time
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Are you trying to figure out the total force of impact-inelastic collision?
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Here you go Coach.
http://www.endmemo.com/physics/inelastic.php That should make it easier for you.
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Are you trying to figure out the total force of impact-inelastic collision?
Yes. Let me explain.
I'm trying to put into words to parents the importance of power and strength. I had a parent come up and say they didn't want their kid to train "too heavy" for fear of injury, I understand that. But what the parent doesn't understand, in order for that kid to have an advantage over a bigger player, we need to make that kid as powerful and explosive to protect him. Although the parent kinda got it, I don't think it resonated to the point where they understood.
I understand force x mass = acceleration in the gym, I'm just not sure that same equation can be used on the field.
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Coach has a good heart.
But God Damn! He is a slow mother fucker!
No offense.
No offense taken by any means. When it comes to stuff like this I'm extremely slow.
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No offense taken by any means. When it comes to stuff like this I'm extremely slow.
Also politics, sociology and history.
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Both players experience the same amount of force on impact.
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I think in this instance you care about Force.
Force = Mass X Acceleration.
The heavier and the faster, the more force you have.
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Do they both lift?
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Both players experience the same amount of force on impact.
But arrive at the point of impact with much different kinetic energies.
;D
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I think in this instance you care about Force.
Force = Mass X Acceleration.
The heavier and the faster, the more force you have.
Careful... force [kg *m*s^-2] = mass x acceleration ≠ mass x velocity = momentum [kg*m*s^-1]
If there is no acceleration, there is no force. There is momentum (mass in motion).
What you need, Coach, is to check out elastic/inelastic collision on wikipedia.
(http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Elastischer_stoß2.gif/400px-Elastischer_stoß2.gif)
(http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Elastischer_stoß3.gif/400px-Elastischer_stoß3.gif)
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Careful... force [kg *m*s^-2] = mass x acceleration ≠ mass x velocity = momentum [kg*m*s^-1]
If there is no acceleration, there is no force. There is momentum (mass in motion).
What you need, Coach, is to check out elastic collision on wikipedia.
(http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Elastischer_stoß2.gif/400px-Elastischer_stoß2.gif)
(http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Elastischer_stoß3.gif/400px-Elastischer_stoß3.gif)
I think the point is to keep it simplistic.
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EDIT: See answer listed in later post - ignore this one, there is a mistake
Say they are both running 15 mph...And say the impact occurs in half a second....
So to calculate the force, you have:
[(Mass 1 * Velocity 1) - (Mass 2 * velocity 2)]/Time in which the collision occurs = Force
Mass 1 = 270 lbs
Mass 2 = 155 lbs
Velocity 1 = 15 m/h = 22 ft/s
Velocity 2 = -15 m/h = -22 ft/s
[(270 lbs * 22 ft/s) - (155 lbs * - 22 ft/s)] / 0.5 seconds =
(5940 lbs*ft/s + 3410 lbs*ft/s ) / 0.5 s =
9350 lb*ft/s / 0.5 s = 18700 lbs * ft/s^2 = 25,853.677 Newtons
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Getbig U is accepting applications ;D
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my answer.
PAIN!
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btw my answer listed above is based on impulse and momentum, and as others stated its based on an inelastic type of collision
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I think the point is to keep it simplistic.
I agree, but... "make things as simple as possible, but not simpler."
To stay on topic: There are two different scenarios after you tackle someone in football, from a physical point of view.
Either the bodies stick together after the collision (which is the case, most of the time, in football, e.g. inelastic collision) or they bounce off of each other (elastic collision).
Since the first case is much more common, here's all you need to know about it:
m1 * v1 + m2 * v2 = (m1 + m2) * vfinal
For example:
Before the collison:
Player 1 (mass = 80 kg) ---- (22 m/s) --> <-- (-4m/s)---- (mass = 120 kg) Player 2
----> positive x-Axis
After the collision:
vfinal = (m1*v1 + m2*v2) / (m1 + m2) = (80*22 + 120*-4) / (80 + 120) = 6.4 m/s (in positive x-Axis) -> Player 1 is overrunning Player 2.
--- (Player 1 + Player 2 = 200 kg)----- (6.4 m/s) --->
If vfinal is negative, Player 2 will overrun Player 1.
That's really as simple as it gets. Now you can calculate how fast a lighter Player has to run to stand a chance against a much heavier Player.
** had to change / to * before vfinal
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Wait I made a mistake somewhere in my last calculation, anyways I adjusted the values based on the speeds you listed:
So to calculate the force, you have:
[(Mass 1 * Velocity 1) - (Mass 2 * velocity 2)]/Time in which the collision occurs = Force
Mass 1 = 270 lbs
Mass 2 = 155 lbs
Velocity 1 = -10 yds / 2 sec = 15 ft / s
Velocity 2 = 10 yds / 1.7 sec = 17 ft / s
Collision occurs in 0.5 seconds
[(270 lbs * 15 ft/s) - (155 lbs * - 17 ft/s)] / 0.5 seconds = 13370 lbs*ft/s^2 = 1,848.46874 newtons
FORCE OF IMPACT = 1,848.46874 newtons
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Wait I made a mistake somewhere, anyways I adjusted the values based on the speeds you listed:
Say they are both running 15 mph...And say the impact occurs in half a second....
So to calculate the force, you have:
[(Mass 1 * Velocity 1) - (Mass 2 * velocity 2)]/Time in which the collision occurs = Force
Mass 1 = 270 lbs
Mass 2 = 155 lbs
Velocity 1 = -10 yds / 2 sec = 15 ft / s
Velocity 2 = 10 yds / 1.7 sec = 17 ft / s
[(270 lbs * 15 ft/s) - (155 lbs * - 17 ft/s)] / 0.5 seconds = 13370 lbs*ft/s^2 = 1,848.46874 newtons
MMMM. Fig Newtons.
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(http://stream1.gifsoup.com/view6/4642914/bag-snatcher-smashes-glass-window-o.gif)
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Wait I made a mistake somewhere in my last calculation, anyways I adjusted the values based on the speeds you listed:
So to calculate the force, you have:
[(Mass 1 * Velocity 1) - (Mass 2 * velocity 2)]/Time in which the collision occurs = Force
Mass 1 = 270 lbs
Mass 2 = 155 lbs
Velocity 1 = -10 yds / 2 sec = 15 ft / s
Velocity 2 = 10 yds / 1.7 sec = 17 ft / s
Collision occurs in 0.5 seconds
[(270 lbs * 15 ft/s) - (155 lbs * - 17 ft/s)] / 0.5 seconds = 13370 lbs*ft/s^2 = 1,848.46874 newtons
FORCE OF IMPACT = 1,848.46874 newtons
Wow, ok. Can this be translated into lbs per sq in?
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Do they both lift?
Of course. It's HS football. The RB is a 420lb squatter.
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Keep in mind that both individuals will be hit with equal force...
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Wow, ok. Can this be translated into lbs per sq in?
http://www.unitconversion.org/force/newtons-to-pound-forces-conversion.html
might help
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Wow, ok. Can this be translated into lbs per sq in?
Give me a few minutes coach - think I can do something for you.
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Give me a few minutes coach - think I can do something for you.
Thanks. Appreciate it.
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Yeah as stated above:
1 848.46874 newtons = 415.552304 pound force which is really equivalent to a gravitational measurement exerted on a mass.
I have not included Pounds/squre inch because I don't know the heights and widths of those two players Send me this info and maybe we can come up with some rough estimates.
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Keep in mind that both individuals will be hit with equal force...
How would it be equal force if the RB is approximately 115-120lbs less and is traveling at a higher rate? Seems to be the RB would be generating more power.
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How would it be equal force if the RB is approximately 115-120lbs less and is traveling at a higher rate? Seems to be the RB would be generating more power.
Yes but they both feel the same impact. Regardless if one can suppress the impact (take the hit) more.
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Yeah as stated above:
1 848.46874 newtons = 415.552304 pound force which is really equivalent to a gravitational measurement exerted on a mass.
I have not included Pounds/squre inch because I don't know the heights and widths of those two players Send me this info and maybe we can come up with some rough estimates.
Ok, remember this is a hypothetical but the RB is real. He's 5'8 155 and the O Linemen would be approximately 6-6'3 270-80.
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Yes but they both feel the same impact. Regardless if one can suppress the impact (take the hit) more.
[/quote
Got it!
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Ok, remember this is a hypothetical but the RB is real. He's 5'8 155 and the O Linemen would be approximately 6-6'3 270-80.
Ok - I played football in high school, lets get in some other details.... lol
The two players won't be running into each other standing upright...
The O lineman will hit with his shoulder.... so I need to know what his shoulder measurements are (roughly) and we will only use one side of his shoulders since thats what he'll be hitting with....
The running back will most likely absorb the hit with his abs or waist... so would be a good idea to know what his waist measures... unless he crouches down and delivers a hit with one of his shoulder pads - so then we'd need to know his shoulder measurements.
Give me some rough numbers here and I could translate it into Pounds per square inch for you.
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Btw - Its here that they will have different Pounds per square inch values, since their measurements will be different. We already told you the force generated from that hit, the PSI kinda tells you how each player will absorb the hit.
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Actually no, the Pounds per square inch will still be the same, because the impact area is the same size... so your answer will be..... (give me a minute here).....
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Sorry Coach - gonna need a little bit more time!
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Coach, I have serious doubts that showing some parents physics breakdowns, will land you a client.
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Coach, a physical demonstration would be much more helpful for the parents instead of all this math and physics. Just have a normal sized human male bump into you while walking, and since you're only 3'2" you'll fly about 10 feet and this will demonstrate to the parents that their son needs to get on steroids and join your bulking program.
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Coach, a physical demonstration would be much more helpful for the parents instead of all this math and physics. Just have a normal sized human male bump into you while walking, and since you're only 3'2" you'll fly about 10 feet and this will demonstrate to the parents that their son needs to get on steroids and join your bulking program.
Lol!!!!
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Coach, a physical demonstration would be much more helpful for the parents instead of all this math and physics. Just have a normal sized human male bump into you while walking, and since you're only 3'2" you'll fly about 10 feet and this will demonstrate to the parents that their son needs to get on steroids and join your bulking program.
Coach....you could always smash your 1974 Pinto head first into an oncoming train at a very high rate of speed to show your prospective clientelle how much "power" you generated and how little the train felt it.
You may learn a thing or two about mass and momentum in the process.
;D
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You also have to factor in the coefficient of friction at the point of impact for both players. Did both players have a foot on the ground or were in between strides? This is important for transference of power. There are to many variables not even mentioned like leverage due to height and placement of the hit whether high or low. Of all the factors speed and weight are the most important.
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You also have to factor in the coefficient of friction at the point of impact for both players. Did both players have a foot on the ground or were in between strides? This is important for transference of power. There are to many variables not even mentioned like leverage due to height and placement of the hit whether high or low. Of all the factors speed and weight are the most important.
no, friction is already factored into the velocity, it won't effect the force of collision
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Coach....you could always smash your 1974 Pinto head first into an oncoming train at a very high rate of speed to show your prospective clientelle how much "power" you generated and how little the train felt it.
You may learn a thing or two about mass and momentum in the process.
;D
Thats funny, that was actually my first car..hahahahaha. A 74' Pinto ;D
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Ok - I played football in high school, lets get in some other details.... lol
The two players won't be running into each other standing upright...
The O lineman will hit with his shoulder.... so I need to know what his shoulder measurements are (roughly) and we will only use one side of his shoulders since thats what he'll be hitting with....
The running back will most likely absorb the hit with his abs or waist... so would be a good idea to know what his waist measures... unless he crouches down and delivers a hit with one of his shoulder pads - so then we'd need to know his shoulder measurements.
Give me some rough numbers here and I could translate it into Pounds per square inch for you.
True, it would be multiple. But for the sake of argument, I'm using one as an example.
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Coach, I have serious doubts that showing some parents physics breakdowns, will land you a client.
This is to the parent(s) of an existing client. Every so often we hold seminars to help explain our programs. Using examples like this helps explain the "why's" of our program. Although, it would be impossible for ME to go into the detail that BIG ACH is explaining. This is good stuff right here.
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I agree, but... "make things as simple as possible, but not simpler."
To stay on topic: There are two different scenarios after you tackle someone in football, from a physical point of view.
Either the bodies stick together after the collision (which is the case, most of the time, in football, e.g. inelastic collision) or they bounce off of each other (elastic collision).
Since the first case is much more common, here's all you need to know about it:
m1 * v1 + m2 * v2 = (m1 + m2) * vfinal
For example:
Before the collison:
Player 1 (mass = 80 kg) ---- (22 m/s) --> <-- (-4m/s)---- (mass = 120 kg) Player 2
----> positive x-Axis
After the collision:
vfinal = (m1*v1 + m2*v2) / (m1 + m2) = (80*22 + 120*-4) / (80 + 120) = 6.4 m/s (in positive x-Axis) -> Player 1 is overrunning Player 2.
--- (Player 1 + Player 2 = 200 kg)----- (6.4 m/s) --->
If vfinal is negative, Player 2 will overrun Player 1.
That's really as simple as it gets. Now you can calculate how fast a lighter Player has to run to stand a chance against a much heavier Player.
** had to change / to * before vfinal
where have you been? :o
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Ok....
Say the impact area is 50 sq/inches...
Then your Pounds per square inch (PSI) is: 415.55 lbs per 50 sq inches...
Or 8.311 lbs per sq. inch
Coach you have to remember, force of impact (like car crashes) are not measured in PSI... they are measured in Force (Newtons or Pounds-Force as stated earlier), which is why we calculated how long the collision took place.
Its hard to calculate this on paper, but The size of the player will positively increase force, the bigger he is, the higher the force, but it will most likely also take longer to stop him (time of collision), and the longer the time of collision is, the less force there will be experienced by said player.
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no, friction is already factored into the velocity, it won't effect the force of collision
affect ::)
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This is to the parent(s) of an existing client. Every so often we hold seminars to help explain our programs. Using examples like this helps explain the "why's" of our program. Although, it would be impossible for ME to go into the detail that BIG ACH is explaining. This is good stuff right here.
so you want to shoot off a bunch of rapid-fire figures to bamboozle them into giving you money? ;D
but really, you know F = MA -- if your goal is to explain to parents why kids need to "be explosive", why not just say,
"Force equals mass times acceleration. So, if your son has less mass than the opposing lineman, he needs to accelerate more in order to match the lineman's force output. Here's how our training system can maximize your son's acceleration potential... [insert bullshit training explanations here :D]."
imo, this would be a much clearer and more straightforward way of convincing parents than trying to walk them through some sort of worked out equation which you don't even fully understand yourself.
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affect ::)
auto correct on my phone (dunno why) bitch! ;D
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so you want to shoot off a bunch of rapid-fire figures to bamboozle them into giving you money? ;D
but really, you know F = MA, if your goal is to explain to parents why kids need to "be explosive", why not just say,
bingo - simple and to the point...
Bigger players, and faster players will generate more force!
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Coach here is a video that goes into some details behind the physics of a football tackle
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Thats funny, that was actually my first car..hahahahaha. A 74' Pinto ;D
Is this it? I got the Title work on it.
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bingo - simple and to the point...
Bigger players, and faster players will generate more force!
Read WAY earlier in the thread... It was said previously.
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Is this it? I got the Title work on it.
Similar. It was a gold color. You have MY original title??
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This is to the parent(s) of an existing client. Every so often we hold seminars to help explain our programs. Using examples like this helps explain the "why's" of our program. Although, it would be impossible for ME to go into the detail that BIG ACH is explaining. This is good stuff right here.
Then Google-Fu the physics of a football tackle and read up.
Big Ach is close but he has left out the element of Impulse in a tackle. You'd think a suicide bomber in training like Toucan Sam would know better. ;D
Forget all this math nonsense Chico, just tell the kids to take the shortest distance to the ball carrier, get there as fast as possible, and arrive in ill humor. They'll get it. ;D
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Similar. It was a gold color. You have MY original title??
Yea I got it. ;D
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Then Google-Fu the physics of a football tackle and read up.
Big Ach is close but he has left out the element of Impulse in a tackle. You'd think a suicide bomber in training like Toucan Sam would know better. ;D
Forget all this math nonsense Chico, just tell the kids to take the shortest distance to the ball carrier, get there as fast as possible, and arrive in ill humor. They'll get it. ;D
my whole formula was based on impulse homie!!!
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my whole formula was based on impulse homie!!!
There will be no partial credit for 35 year old Arab "students" with expired visas and a C4 laden vest hanging in their closet. ;D
Beak Ach! ;D
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There will be no partial credit for 35 year old Arab "students" with expired visas and a C4 laden vest hanging in their closet. ;D
Beak Ach! ;D
lol
I'm American homie - Proud and free! 8)
(https://sphotos-a.xx.fbcdn.net/hphotos-ash3/255098_10101776806267844_164572178_n.jpg)
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lol
I'm American homie - Proud and free! 8)
(https://sphotos-a.xx.fbcdn.net/hphotos-ash3/255098_10101776806267844_164572178_n.jpg)
So what makes you American....the 14-inch arm or the 87% bodyfat?
You look like the kind of guy that drycleans his underwear.
;D
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So what makes you American....the 14-inch arm or the 87% bodyfat?
You look like the kind of guy that drycleans his underwear.
;D
Well, my naturalization certificate for starters...
And no... your mom prefers to lick the inside of my underwear clean for me when called upon! So no need for dry cleaners!
;)
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Well, my naturalization certificate for starters...
And no... your mom prefers to lick the inside of my underwear clean for me when called upon! So no need for dry cleaners!
;)
Naturalization certificate? You marry Tbombz for a green card?
1981 called and said Lionel Ritchie wants his hair back...
;D
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Thanks guys for help on this, it really helped figure some things out. This is the kind of stuff that isn't touched upon when I go to seminars or clinics and have never heard this question asked at one. Thanks again.
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Naturalization certificate? You marry Tbombz for a green card?
1981 called and said Lionel Ritchie wants his hair back...
;D
Yeah I got nothing for that ;D
TBombz was willing... I couldn't resist! LOL
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Yeah I got nothing for that ;D
TBombz was willing... I couldn't resist! LOL
I know.....I saw your blushing bride Facebook updates.
So what exactly is this "felching" you guys keep referring too?
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(http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Elastischer_stoß2.gif/400px-Elastischer_stoß2.gif)
Hit in order
4, 1, 2, 3.
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Thanks guys for help on this, it really helped figure some things out. This is the kind of stuff that isn't touched upon when I go to seminars or clinics and have never heard this question asked at one. Thanks again.
Coach, keep in mind, football tackles (collisions) are different than a car crash between two inanimate objects. Watch video of Bo Jackson, Earl Campbell , or John Riggins to see that power, speed, balance and leg drive will go a long way in determining who comes out on top in an on field collision.
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ONLY love for Coach. Great human being. Will give the shirt off of his very back.
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ONLY love for Coach. Great human being. Will give the shirt off of his very back.
Did your phone change "wet" to "very"?
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Coach, keep in mind, football tackles (collisions) are different than a car crash between two inanimate objects. Watch video of Bo Jackson, Earl Campbell , or John Riggins to see that power, speed, balance and leg drive will go a long way in determining who comes out on top in an on field collision.
Yes, of course. I completely understand that. Thanks
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ONLY love for Coach. Great human being. Will give the shirt off of his very back.
Thanks Steve, appreciate that.
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Coach, keep in mind, football tackles (collisions) are different than a car crash between two inanimate objects. Watch video of Bo Jackson, Earl Campbell , or John Riggins to see that power, speed, balance and leg drive will go a long way in determining who comes out on top in an on field collision.
Power, Speed, and balance all determine mass and acceleration. They are all intertwined.
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Phsysics club.
(http://cdn01.dailycaller.com/wp-content/uploads/2011/03/nerdh-e1299432797100.jpg)
Do I remember right that kinetic energy is mass * velocity squared?
Not sure if billiard balls or similar ideal objects make a good comparison. I agree with previous posters that a foot on the ground would transfer force and negate calculations predicated on colliding bodies being unsupported. The angle of incidence with the ground would be critical. There's also the problem that the two players aren't shaped like blocks or spheres and won't be hitting one another center to center, so they are going to rotate around one another and the transfer of energy wouldn't be 100%. A human form will also buckle and change shape at impact, unlike a billiard ball or ideal object, so you've got moments of torque and a shifting center being introduced by the change in shape of the two players bodies in addition to linear vectors. And an unlucky player's body would buckle at a point where the force of impact is sufficient to overcome the integrity of a joint.
In all, an increase in velocity will do more to increase the force of impact than an increase in mass. When I was a kid, maybe 70 or 80lbs, I knocked a big fat dude a long way when I skied into him.
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Power, Speed, and balance all determine mass and acceleration. They are all intertwined.
power = work done / time
work done is force x distance. force = mass x acceleration.
acceleration = velocity/time
so power = mass x velocity/time x distance/time
= (mass x velocity x distance) / time^2