Pure maths, physics, logic (braingames.ru): non-trade-related brain games - page 24

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TheXpert:

One.

Two.

Decide :) The first point is two to three. The second -- three to five.

Let's skip the absolute, or we'll just say it's in the law of physics.
 
Zeleniy: Let's not make up absolutely, otherwise we can make up things like that, let's just say there is a law of physics.

No, it's fine. The initial problem is checked practically - but this is the statement of the moderator of braingames.ru.

By the way, so far, as I understand it, no one, apart from the Expert, has understood the physical meaning of the problem, i.e. the processes. Where does "almost 25 cm" come from? - nobody knows yet, but the Expert has seen it :)

No, it's a virus, I didn't expect that...

 
TheXpert:

Oh, hmm, here's a challenge.

A brick is thrown onto a perfectly elastic spring from a height of one metre. The spring is fixed. All energy transfer occurs only between the brick and the spring.

How high will the brick jump :)

To an absolutely high height of 1 meter, if I understand correctly, there is a clue in this problem too, it's written right there =)
 
Zeleniy:
To the absolute height of one metre.
Nah, a little less.
 
TheXpert:

A brick is thrown onto a perfectly elastic spring from a height of one metre. The spring is fixed. All energy transfer occurs only between the brick and the spring.

How high will the brick go :)

A meter, for fuck's sake, how much more. It's like if it falls on an elastic surface.
 
TheXpert: Nah, a little less.
The spring will start to wobble. That's not fair. Indeed, the brick will jump a little less than a metre as it will have to transfer some of its energy to the oscillation of the spring.
 
TheXpert:
Nah, a little less.

1 metre minus the length of the compressed spring.

Am I in the right direction ?

 
Mathemat:
The spring will start to oscillate. That's not fair.
Mm-hmm ) And why is it unfair?
 
Zeleniy:

1 metre minus the length of the compressed spring.

Am I in the right direction ?

No. The length of the compressed spring is irrelevant.
 
TheXpert: Uh-huh ) and why is it unfair?

Because we've been taught all our lives in school that the bounce rate will be the same as the acceleration rate. Then you have to think about what a perfectly elastic collision is.

If the spring is heavy and very soft, then clearly less than a metre will come out.

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