Zhong Ding - Understanding Force

[origami_itto]

Everyone knows Force equals Mass times Acceleration, but that’s not the whole story by a long shot.

This information has endangered friendships...
https://atomictaichi.com/2023/12/07/und ... ing-force/

Force is usually understood by the layperson as “Mass times acceleration” or F=MxA.

For most purposes in martial arts, this is a sufficient understanding. We can talk about an object, like a fist, moving at a speed when it makes contact with a face and the force equation expresses the energy exchange very well in that context.

What we don’t consider, usually, is that this is just a measure of the difference of unbalanced forces. Without movement, specifically without a change in velocity, it is not a meaningful formula. It measures “net force” not “total force” or “applied force”. Only force that is successful in accomplishing work, not all of the forces involved in making something happen, in reality, this just measures the excess force.

[Bhassler]

I think you're conflating Force with Kinetic Energy, Momentum, Power, and maybe some other things, which leads to an inaccurate representation of what "force" means. That doesn't invalidate the rest of what you're saying by an means, but it does detract from the overall coherence and message of the article. Purely from a writing perspective, F=ma is fine as a hook and to set the stage, but I would more quickly establish that you're talking about what people "think of" as force and make it very clear that you are not talking about the literal meaning of the equations.

[origami_itto]

I think you're conflating Force with Kinetic Energy, Momentum, Power, and maybe some other things, which leads to an inaccurate representation of what "force" means. That doesn't invalidate the rest of what you're saying by an means, but it does detract from the overall coherence and message of the article. Purely from a writing perspective, F=ma is fine as a hook and to set the stage, but I would more quickly establish that you're talking about what people "think of" as force and make it very clear that you are not talking about the literal meaning of the equations.

They do get kind of tricky.

Kinetic energy would be more like E = mass*speed.
EDIT (thanks ParadoxTeapot) : It actually IS
KE = 1/2(m)s^2 or half of mass times speed squared.

Unbalanced/net force is F = mass*CHANGE in speed

What gets confusing is that we only think about it when they collide.

For example you have a 100kg mass moving at 9.8m/s, the formula for energy is KE = .5*m * s^2 so E = 2401 Joules.

If we're in a frictionless vacuum with no gravity then there is no "force' present, just that kinetic energy.

If it were to hit a brick wall, then it and the brick wall would exert a force of 980 Newtons against each other.

If it were to be caught in Earth's gravity well and start falling, then gravity would exert a force of 980 newtons every second, 9.8m/s^2 acceleration, increasing the speed and kinetic energy while the force remains constant.

So if it falls for ten seconds, then it will be moving at 98 m/s and be carrying 240100 Joules of energy when it impacts the earth and then both will exert 9800 Newtons of Force against each other.

So they are closely related, and kinetic and potential energy are definitely at play, but they are talking about different points in the process.

Kinetic energy = how much energy something has by virtue of mass and motion
Force = how much energy is involved in making something change its motion

Thank you for reading and taking the time to respond!

[origami_itto]

I think I could make that a little more clear and be more precise about what I'm discussing there...

This whole thing was in response to somebody trying to use f=ma to explain everything.

[wayne hansen]

It’s impossible to explain something verbally using science that your body does not understand

[origami_itto]

It’s impossible to explain something verbally using science that your body does not understand

Is that true?
Does your body understand flight? Science does a great job of explaining it.
Nuclear fusion? Tropospheric scatter radio? MRI imaging?

We're talking about force and energy here. I welcome your insight into the errors.

[Steve James]

Technically, acceleration isn't exactly the same as velocity, especially when it comes to "F"orce. Acceleration is a change in velocity over time.
Velocity also describes a vector (a line having a direction).

In tcc, it might be described as the difference between a push and a punch. Not to mention, F can be increased by reducing the surface area on a target (as in trying to poke a hole with the handle of the ice-pick or the tip. I.e., one will take more effort than another. But, afa F, though, what we're really concerned about is the effect, not the amount. (4ozs v 1000lbs... sorta).

Anyway, the old question is whether you'd prefer to be hit by a 10,000lb locomotive going 1 mph or a 1lb ball going 10000 mph. But, there's no way to stop either without using an equal amount of force. Of course, it's easy to step out of the locomotive's path.

A student of Tian Zhaolin, iirc, wrote a book discussing physics and tcc. I forget the name. Lemme see if it's in the library or I didn't lend it away.

"Tai Chi Chuan: Its Effects and Practical Applications," by Yearning K. Chen.

[origami_itto]

Technically, acceleration isn't exactly the same as velocity, especially when it comes to "F"orce. Acceleration is a change in velocity over time.
Velocity also describes a vector (a line having a direction).

That's what I'm talking about here.

What we don’t consider, usually, is that this is just a measure of the difference of unbalanced forces. Without movement, specifically without a change in velocity, it is not a meaningful formula. It measures “net force” not “total force” or “applied force”. Only force that is successful in accomplishing work, not all of the forces involved in making something happen, in reality, this just measures the excess force.

The force of gravity will bend the vector of a flying object towards the earth, for example. I struggle to find the right level of detail for each of the concepts.

In tcc, it might be described as the difference between a push and a punch. Not to mention, F can be increased by reducing the surface area on a target (as in trying to poke a hole with the handle of the ice-pick or the tip. I.e., one will take more effort than another. But, afa F, though, what we're really concerned about is the effect, not the amount. (4ozs v 1000lbs... sorta).

Anyway, the old question is whether you'd prefer to be hit by a 10,000lb locomotive going 1 mph or a 1lb ball going 10000 mph. But, there's no way to stop either without using an equal amount of force. Of course, it's easy to step out of the locomotive's path.

That's exactly why I think the difference is important.

I had a friend who worked offshore and was standing a little too close to the trash compactor barrel when it swung out. I can't provide any meaningful numbers on the mass but I estimate it was over a ton, easily. We're talking about something that's taking all the trash on a drilling rig for maybe a month at a time, solid steel.

It came off the rail and fell a few feet, just tilted before it got caught by a safety, but enough for it to hit him in the head, sever his optic and olfactory nerves.

It was moving very slow, and did not move very far, he just didn't dodge quick enough. He's a millionaire. A blind millionaire that can't smell.

A student of Tian Zhaolin, iirc, wrote a book discussing physics and tcc. I forget the name. Lemme see if it's in the library or I didn't lend it away.

"Tai Chi Chuan: Its Effects and Practical Applications," by Yearning K. Chen.

Right on thanks for the tip.

[ParadoxTeapot]

A few corrections.

Kinetic energy is 0.5 * Mass * (Velocity Squared). Velocity and kinetic energy do not have a linear relationship. But the variables are correct.

Momentum, however, is mass * velocity. So, if a giant truck is driving at a constant velocity toward me, it’s still very bad news to me because the momentum is huge.

Force is the change in momentum.

Next correction, force does not increase when the surface area on the target is decreased. What increases is not force but pressure.

Pressure is Force/Area.

A punch and a needle can fly at you with the same force. But the needle penetrates you more because the pressure is much higher due to a lower surface area.

So, in conclusion, physics has actual words and concrete definitions that some of you do not seem to know about.

[Steve James]

Pressure is Force/Area.

But, write that equation where F =

Anyway, corrections accepted, but my point was that we're interested in the effect. You're right, the end of the ice pick will more pressure (psi) on a the area it affects than the handle -using the same amount of force. But, we're not interested in stabbing anyone with a handle. In general, we're trying to utilize force to perform some form of work. Ideally, we'd use as little as possible to perform the same work or accomplish a given goal.

In the locomotive example, part of the point is that's not possible to stop either completely without at least the same force. Since that's not always possible, something else has to be done. Afa tcc and im arts are concerned, the interesting thing is their methods of generating force. Some will argue that it's special; some will say it's an application of physics.

[origami_itto]

So, in conclusion, physics has actual words and concrete definitions that some of you do not seem to know about.

I went to public school in the US and then straight into Military Dad at 19, have been working for a living ever since. Whatever knowledge of anything I have is just due to eclectic interests of the moment pulling my ADHD hyperfocus into a new field of study.

I love being ignorant and wrong because learning something new and more correct is the point and a chance for even more fun.

I put about 8 hours of research into this particular article and still missed some things.

Thanks for reading!

[suckinlhbf]

So much information. We are end-users, and we need an AI Combat Simulation Program on our phone.

[everything]

My dad and his taiji buddies were professional physicists.

It didn’t help them “get it”.

Even if I understood all the equations, I can’t become Shohei Ohtani.

But interesting anyway.

[Steve James]

The equations aren't important. But, Bruce Lee's argument was that a 135lb could hit harder than a 235lb person by moving faster. The "one inch" punch demonstration (ok, it wasn't one inch) was his example of using acceleration (moving from a static position).

Again, the interesting question is how does he do it. The same can be said about examples of people flying away after a touch by someone seated. Now, which explanation anyone accepts is another thing.

[suckinlhbf]

Knowing all or most of the factors, their combination as well as the variations that could improve the quantity of movement helps. And how to make them into our body is even more important than knowing and understanding them. Practice is the only way.