It is not possible for most people because their minds cannot imagine it. The body can only do what the mind wills it to. Have you seen video of Bruce Lee kicking his training partners 12 feet across the room? The force is about 12*140 (1680). Assuming that the sandbag is no more than 5.6 feet from the ceiling, that would be the same amount of force. I'll admit that the .005 second strike does sound exaggerated. The person probably meant to say .05 seconds, which is feasible because Bruce was said to strike in the blink of an eye, which takes place in .01 seconds.
Other people can do some of Bruce Lee's feats, but it was his combination of mind and body that made him special, and the reason that he is still discussed today.
I don't know what you are calculating here. You seem to be multiplying feet travelled by a person's weight in pounds and are equating this to force. Force is actually the product of mass and acceleration. And this acceleration generated by anyone's kick or punch would be transmitted in a very short period of time. Over a very short distance- not the 12 feet you mention. So in fact it would be an Impluse.
I have never ever seen- other than in movies involving wires that are later digitally removed - anyone 'fly' across the room for 12 feet. There may be an initial lift off which would therefor involve another component: namely the force required to lift a person's mass off of the floor. I will ignore this for the time being. Also, the person so struck would become a projectile that would follow a parabolic pathway to the ground. This complicates matters.
And that force is not applied to the person over the entire 12 feet that you say the person travels. The 12 feet will come into play later on should anyone be required to figure out the force impeding the object.
Your comment about the sandbag and same amount of force is completely bogus.
So if the person struck was initially at rest, and his final speed - prior to slowing down - was say 10m/s - perhaps an exaggeration- and this final speed was achieved in 0.5 seconds ( as the body would almost immediately begin to slow down ), then the acceleration would be 20m/s/s. The force needed to get a mass to accelerate thusly would be 1300N assuming a 65 kilogram person. this would approximately equal 2600 Watts of Power generated in that 0.5 seconds.
Any alterations that involve a greater acceleration or a shorter time period ( the "myth " of Bruce Lee ) would create an even greater force and power. And if you reduce the final speed obtained or increase the time- you are bringing the force and power into the realm of the easily attainable.
You are sort of figuring out WorK done which is the product of force and distance. And then Power is work divided by time. you can't use the 12 feet. This is just wrong and shows me that you have no real understanding of what you are talking about. or you just failed every physics course you ever took: if you ever took any.
YOu'd have to convert feet to meters and pounds to kilograms.
3 feet is about 1 meter. Using 0.05 seconds as the time you have a speed of 20 meters per second which reasonable. Its twice as fast as the velocity of a top world class sprinter: Maurice Green say. But you only have to hit it for that short period of time. I couldn't do it but others probably could. hockey Goal tenders for example. maybe
If you want to see how much power 2600 watts actually is, get on a concept 2 rower, set the monitor to watts and then try to hit 1600 let alone 2600. You will have to alter the damper settings.
The math is very simplified here and I didn't consider the effects of gravity on a person lifted completely off the floor nor did i consider the projectile motion parabolic pathway an object would follow.
There is no amount of science that will change people's opinion about what Bruce Lee could and could not do. Stories about what he could do have been passed down over the years and have been exaggerated for effect. Many other well meaning people simply make things up to show how great the guy was. People idolize the guy and for that reason alone, he has done a great deal to help many people overcome their fears and to better themselves.
I once saw him pick up a rickshaw by the ends of the shafts. The rickshaw had 2 or 3 bad guys in it too. The power to do that would be enormous... oh wait.. that was in 'ENter the Dragon.." damn...
