Recent content by BriK

Hrm...trick question? It asks "is zero work done on you"... If I were to carry a box from point A to point B at a constant velocity, is any work done on the box? No, because I am applying a vertical force on the box to equal the effects of gravity while I walk horizontally between...

P = I * E E = V = voltage P = power I = current I like the PIE formula better because its easy to remember the word pie... If P stays the same then only I or E can change...so if you raise E then I must be reduced to keep P the same and vice versa... As someone states above the...

Whenever I pressurize a pressure vessel, I always always always have a safety relief valve in place...even if the compressor cannot develope the pressure needed to burst the vessel...its just a good general safety practice...most safety codes likley require it... Picture if, god forbide, it...

Didnt read every post above so I may have missed this if someone else brought it up, but its stated that the holding or second spring is smaller than the first compressed spring...wouldnt this likley mean, unless the springs were not typically designed, that the wire used in construction of the...

One other thought about the torso twisting into the punch... As you twist not all portions of the torso turn the same amount...plus, if I lift my elbow I increase the diameter at my shoulders out to the length to reach my elbows...so I was thinking, if I segment the torso into several pieces...

Interesting article which may help some... http://memeticsyns.wordpress.com/2007/07/07/playing-the-pennywhistle/ My wife plays the penny whistle and I am trying to learn the bagpipes so this topic interested me...

How about a high-pressure/low-flow gas-duty pump instead of air pressure? Pump the gas in a circle out of the tank and back to the tank continually with the return being thru a needle valve or small orifice or capillary (very small) tube to give the pump something to push against, then T-off...

The resistance of a wire won't change unless you change it physically in some manner...such as in heating it, or lengthening it, etc... Maybe impedence versus resistance...

Here is another link that uses the same formula to define a straight punch (no twisting torso)...so the rotational energy is real low... http://www.pims.math.ca/pi/issue6/page09-11.pdf But he uses "5 pi" for angular velocity...with the fist rotating 180degrees as it extends to completion...

Here is a link to the paper I am looking at for a reference...it may help to see the setup... http://www.phys.ttu.edu/~cmyles/Phys5306/Papers/2004/Physics%20of%20Martial%20Arts.doc Seems to make sense to me, but I cannot explain where the 1.9 value comes from...but yes it could be velocity...

I misspoke, kind of... The torso (35kg) is twisting, not being thrown like the fist/arm, thereby lengthening the punch reach and adding in a rotational energy...The 35kg is used to find the moment of inertia as a component to find the rotational energy... Yes, the arm is 8kg... You are...

Yes the total doesn't add up for me either, its off by a good bit from the 207 J value given in the article I am looking at... Et = (8 kg)(9.8 m/s^2)(0.16 m) + 0.5(8 kg)(7.3 m/s)^2 + 0.5(0.1554 kg m^2)(1.9^2/0.22^2) Et = 12.544 + 213.16 + 0.013576 = 225.72 Is what I get...

35kg is the torso mass but that is not thrown at the opponent...just the 8kg mass of the arm is thrown at the opponents with the torso twisting into it... Yes...d1 and d2 are radius values...

I am trying to figure out the force delivered behind a right rear hand punch as you twist your hips and shoulders into the punch. I have looked at several sources to find most of the information but I am stuck on one part and would appreciate any help. I found an article that helped me...