| Sr.No. |
Mechanical Posers |
| 1 |
The free-rolling wheel:- |
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Imagine a free rolling wheel on a flat surface. But with following initial conditions.
a - the wheel has been set rolling such that there is no slip betwwen it and the surface on which it rolls.
b - The surface is infinitely hard, but has sufficient friction to prevent slip.
c - The wheel is made of material that has a finite elasticity.
Such a wheel will eventually stop rolling. The question is as under:-
Where is actually the force, or the work done, that stops the wheel.
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| 2 |
The two perfectly hard, weightless, inelastic spheres:- |
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Imagine two perfectly hard, inelastic, weightless spheres of identical volume, with following initial conditions.
a - one of them is filled with Hydrogen, the lightest element.
b - The other is totally evacuated.
The question is as under:-
Which sphere will rise faster, and go higher?
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| 3 |
The jet engine:- |
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We all know and say so, that the forward push of a jet engine is due to the reaction to the action of high
speed exhausting of gasses from the engine. But the question is as under:-
At which point precisely is the "push" to the engine delivered?
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| 4 |
Low pressure Tyres:- |
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We all know that airplanes such as Jumbos use Low pressure tyres. What is the need to do that?
Certainly the planes could use normal tyres just as well? Could you tell?
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| 5 |
In space:- |
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Out in space on an airless earthlike planet turning west to east, you start a slow ascent from the surface.
As you lumber slowly upward, you keep track of what is happening below.
What really will happen, in the course of a few hours, that will shock you? (Apart from the perfectly normal
fact that things below will be appearing much smaller as time passes?
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| 6 |
A Black-hole "what if":- |
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If the sun were to be converted into a black hole this instant, what would be the effect on earth gravitywise? |
| 7 |
Journey to center of the earth :- |
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In a hypothetical hole passing right through and through the earth, would your weight increase or decrease?
What would be the situation weight-wise at the earth's center?
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| 8 |
Reversal riddle :- |
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Do you really think it is possible as some people have suggested, that the earth has a number of times in its
long past, actually reversed its rotation?
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| 9 |
The Tugging engines:- |
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On a railway track are two trolleys mounted with winches. The two are separated by some distance from
each other. One of them has a stronger winch and is lighter. Both are pulling on a common cable.
As the two tug on the line, which trolley do you think will yield ground?
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| 10 |
Space Station problem :- |
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On a space station where a number of families are being raised, a child with a gun that shoots out a ball, is
playing in the large (by space station standards) corridor running around the station.
The child points his gun directly upwards, (reading his calibration dial to 90 degrees), and fires a ball up,
fully expecting it to either go all the way up and hit the ceiling, or somehow come down to it.
But something strange happens. What?
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