Boards Don't Hit Back...Or Do They?!

[MaxMarks]

Just to be sure I wait until the board throws the first punch.

[bushido_man96]

In all actuality, Newton's 3rd law will lead you to understand that the board hits you as hard as you hit it. Breaking it is more a matter of density and leverage than force.

There you go ruining a favorite Martial Arts quote with scientific theory. Kidding aside, I have had a board hit me back when trying to break with a knife hand strike. I still hate that breaking technique....

[sensei8]

In all actuality, Newton's 3rd law will lead you to understand that the board hits you as hard as you hit it. Breaking it is more a matter of density and leverage than force.

There you go ruining a favorite Martial Arts quote with scientific theory. Kidding aside, I have had a board hit me back when trying to break with a knife hand strike. I still hate that breaking technique....

[evergrey]

Also I discovered that if one of my instructors is HOLDING a board, and I punch through it and go a bit far, punching THEM as well, well... I shouldn't apologize. If I apologize, I have to do push ups.

So boards can kind of give you push ups too, lol!

[sensei8]

Also I discovered that if one of my instructors is HOLDING a board, and I punch through it and go a bit far, punching THEM as well, well... I shouldn't apologize. If I apologize, I have to do push ups.

So boards can kind of give you push ups too, lol!

[evergrey]

OSU Bob! Heeeey can you get on facebook chat? Pretty please?

[shadowspawn]

This reminds me of a time years ago when I wanted to practice breaking for the heck of it. I grabbed a bunch of fencing boards (cause we had extra boards lying around that we were never gonna use) and went at it. The first one I took, I broke it and it splintered in a kind of zig zag across the middle. Gave my hand a little rest for a bit and grabbed the second one. Here is where it gets hilarious. My friend also tried to do the same thing on this second board. He made impact and didn't break it. Needless to say he was ticked and his hand was hurting LOL. So then my turn comes up. I hit that thing as hard as I can and it snaps just like the last one but this time the left side of the fencing board flies up using the cinderblock I was using to hold it up as a fulcrum and smacks me right on the side of the head. Bruce Lee definitely lied when he said boards don't hit back LOL

[shadowspawn]

In all actuality, Newton's 3rd law will lead you to understand that the board hits you as hard as you hit it. Breaking it is more a matter of density and leverage than force.

I'm not sure if it's all psychological or not, but it sure feels like it hits back a lot harder if you don't break the board. I've had that happen to me when I was trying to break concrete the first few times. You learn fast that it's best not to be intimidated by it. The more scared you are, the more it's gonna hurt LOL

[sensei8]

This reminds me of a time years ago when I wanted to practice breaking for the heck of it. I grabbed a bunch of fencing boards (cause we had extra boards lying around that we were never gonna use) and went at it. The first one I took, I broke it and it splintered in a kind of zig zag across the middle. Gave my hand a little rest for a bit and grabbed the second one. Here is where it gets hilarious. My friend also tried to do the same thing on this second board. He made impact and didn't break it. Needless to say he was ticked and his hand was hurting LOL. So then my turn comes up. I hit that thing as hard as I can and it snaps just like the last one but this time the left side of the fencing board flies up using the cinderblock I was using to hold it up as a fulcrum and smacks me right on the side of the head. Bruce Lee definitely lied when he said boards don't hit back LOL

[DWx]

In all actuality, Newton's 3rd law will lead you to understand that the board hits you as hard as you hit it. Breaking it is more a matter of density and leverage than force.

I'm not sure if it's all psychological or not, but it sure feels like it hits back a lot harder if you don't break the board. I've had that happen to me when I was trying to break concrete the first few times. You learn fast that it's best not to be intimidated by it. The more scared you are, the more it's gonna hurt LOL

Not just psychological but mechanics again, specifically, impulse or the change of momentum. When you break a board you'll experience a slight deceleration as your fist comes into contact with the surface. If you don't break, that deceleration takes your speed down to zero and the force you feel is greatly increased. Let's see if I still remember high school mechanics (with a bit of help from Wikipedia)

Impulse is

Force x time = mass x change in velocity

so Force = (mass x change in velocity) / time

Say the fist is ~ 0.5 kg, you're punching at 10 ms^-1 and the contact time with the board is 0.01 s. If you break the board you you're decelerating to 9.5 ms^-1, if you don't break, you'll go down to 0 ms^-1.

Breaking the board:

Force = (0.5 kg x 0.5 ms^-1) / 0.01 s

Force = 25 N

Not breaking:

Force = (0.5 kg x 10 ms^-1) / 0.01 s

Force = 500 N

Ouch. So there you go, the force you feel if you fail to break the board is 20 times more than if you'd broken. And that isn't even using proper numbers.

This reminds me of a time years ago when I wanted to practice breaking for the heck of it. I grabbed a bunch of fencing boards (cause we had extra boards lying around that we were never gonna use) and went at it. The first one I took, I broke it and it splintered in a kind of zig zag across the middle. Gave my hand a little rest for a bit and grabbed the second one. Here is where it gets hilarious. My friend also tried to do the same thing on this second board. He made impact and didn't break it. Needless to say he was ticked and his hand was hurting LOL. So then my turn comes up. I hit that thing as hard as I can and it snaps just like the last one but this time the left side of the fencing board flies up using the cinderblock I was using to hold it up as a fulcrum and smacks me right on the side of the head. Bruce Lee definitely lied when he said boards don't hit back LOL

kinda reminds me of a time with my dad. This guy thinks he's never ever wrong and when he is he will never apologise or admit defeat. So me and my sister make it our personal mission to one-up him wherever possible. Had just gotten a brand new plastic rebreakable board delivered. This thing is hard. I personally reckon it must be equivalent to around 3 or 4 wooden boards and a lot less forgiving if you get it wrong. So my dad comes up wanting to have a look and starts going on about all this TKD lark being easy and its all a matter of the right leverage etc. I tell him "go on then, prove it, if I can break it so can you". Get him and my sister to brace it and I break it. Then its his turn. Smacks it as hard as he can with a punch and just stops dead on the board. Look on his face was priceless. Asked him if he was ok and he just mutters something and goes off into the garage to do manly things. Found out later via my mum he'd been sitting there with a bag of peas on his hand and kept hiding it down the side of the chair when I came downstairs