Calculating sand penetration of ice solid from height X

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Discussion Overview

The discussion revolves around calculating the necessary drop height for a timber stick encased in ice to penetrate a sand substrate to a specified depth. Participants explore the physical principles involved, including the effects of substrate properties and the geometry of the ice structure.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes a scenario involving a 30cm timber stick frozen in ice, seeking to determine the drop height required for a specific penetration depth into sand.
  • Another participant questions the feasibility of achieving the proposed penetration depth, suggesting that the dimensions of the stick may have been miscommunicated.
  • Concerns are raised about the variables affecting penetration, including the composition and moisture content of the sand, the angle of the ice, and the mass of the ice.
  • A suggestion is made to refer to "young penetration equations" from a Sandia report, assuming the ice remains intact during the drop.
  • There is a reiteration of the original scenario, emphasizing the discrepancy in the stick's length and its implications for the calculations.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of the proposed scenario and the implications of the stick's dimensions. There is no consensus on the exact calculations or methods to achieve the desired penetration.

Contextual Notes

Participants note that various factors, such as the properties of the sand and the geometry of the ice, could significantly influence the outcome, but these factors remain unresolved in the discussion.

MattRNR2
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G’day physics forum

This is a purely hypothetical question and my knowledge of physics is rather limited so I’ve no idea if answering it is even possible however here goes:

Imagine a 30cm long timber stick approximately 3mm in diameter that has been placed vertically in an inverted pyramid or conical mold (approximately the size of a ice-cream cone) filled with water and frozen so when removed it is frozen in the middle of a solid block of ice that tapers to a point.

I’m trying to work out at what altitude this object would need to be dropped in order to impact a surface composed of a certain substrate (say sand) and penetrate such that n cm (say 40cm) of the timber post would be exposed above the surface and the block of ice and ‘1m – n cm’ (i.e. 60cm) were buried beneath the surface.

I’m guessing such an equation would require a measure of the substrate density, weight and dimension of the ice and gravitational acceleration.

If anyone out there has any idea how this can be achieved or at the very least whether or not this can be achieved give us a yell.

Regards

MattRNR2

Incidentally there is a beer riding on this so suffice to say I'm taking it pretty seriously
 
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MattRNR2 said:
30cm long timber stick
MattRNR2 said:
(say 40cm) of the timber post would be exposed above
MattRNR2 said:
and ‘1m – n cm’ (i.e. 60cm) were buried beneath the surface.
MattRNR2 said:
can be achieved
"Achieved?" Yes, ... BUT ...
Most "bar bets" are rigged. The rigging on this bet may be as simple as stretching the 30 cm stick to 1 meter. If that's just a transcription artifact, sure, there are ways to work out drop heights for what you've described.
 
It will depend on the sand (composition, amount of water, ...), the angle of the ice, the mass of the ice and many other factors.

60 cm sounds very problematic with an ice-cream-cone-shaped object.
 
Google "young penetration equations" for a Sandia report. Assuming that the ice remains intact, they should work.
 
MattRNR2 said:
Imagine a 30cm long timber stick approximately 3mm in diameter that has been placed vertically in an inverted pyramid or conical mold (approximately the size of a ice-cream cone) filled with water and frozen so when removed it is frozen in the middle of a solid block of ice that tapers to a point.

I’m trying to work out at what altitude this object would need to be dropped in order to impact a surface composed of a certain substrate (say sand) and penetrate such that n cm (say 40cm) of the timber post would be exposed above the surface and the block of ice and ‘1m – n cm’ (i.e. 60cm) were buried beneath the surface.
and your 30cm stick suddenly became 100cm ( 1m) long ??