Pure maths, physics, logic (braingames.ru): non-trade-related brain games - page 82

 
TheXpert:
Are you sure? The friction force isn't going anywhere.
Well, I can pull slowly for the first five minutes, and then pull sharply, or stop pulling in the middle of the process, when the box is already accelerated, and then start again. The main thing is that the integral of the forces along the path should be equal to the required energy, and there are a million possible forms of the force curve, including failures to zero.
 
Mischek:
I don't know, we're a democracy.
Oh, well, then of course...
 
Mathemat:

The spring doesn't give a fuck, it's part of the compound body. imho.

Well, well.

Imagine a couple hundred small 1 kg weights connected by springs. A good kick to the end of this pyramid will easily knock it off from start to finish.

Wobbly, naturally.

It is unlikely that just a "good kick" will be enough for one 200kg weight. A very good kick is needed, i.e. much bigger.

 
alsu:
Well, I can pull slowly for the first five minutes and then pull sharply, or even stop pulling in the middle of the process.
Vector, not module. You can't pull sharply because it's a force.
 
TheXpert:
It is a vector, not a module. You can't pull it sharply, because it's a force.

So we only change the direction, but the module remains constant throughout the process? Then it is more interesting. I have to think it over.

But it's realistic for lunatics. I foresee a variation equation.

 
In general, when they say 'coefficient of friction', they mean the coefficient of resting friction, not sliding friction. Therefore, K is the coefficient needed to calculate how the body slides off the ground.
 
MetaDriver:

Well, well.

Imagine a couple hundred small weights of 1 kg connected by springs. A good kick in the end of this pyramid will easily knock it down from start to finish.

Wobbly, of course.

It is unlikely that just a "good kick" will be enough for one 200 kg weight.

Yeah, and you have to connect the train wagons with springs, what an economy. Yes, on nothing.
 
alsu:
Well, I can pull very slowly for the first five minutes, and then pull sharply, or even stop pulling in the middle of the process, when the box has already accelerated, and then start again. The main thing is that the integral of the forces along the path should be equal to the required energy, and there are a million possible forms of the force curve, including failures to zero.

Nah. The most effective thing is to accelerate the baby by alternating the inversion of force at the moments of greatest compression/expansion. Then the required force generally tends to that which is necessary to move the small body - the ogism will come when the corresponding kinetic energy is accumulated.

 
joo:
In general, when they say 'coefficient of friction', they mean the coefficient of resting friction, not sliding friction. Therefore, K is the coefficient needed to calculate how the body slides off the ground.

The concept of "coefficient of friction at rest" does not exist in school problems at all, because the force of friction at rest depends on the applied force (and is equal to it), and not on the weight of the body, in relation to which the coefficient is calculated at all.
 
Mischek:
Yes, and you have to connect the railway cars with springs, what an economy. It's a waste of time.
Well, if they only had to be moved, then yeah. :)