supercat
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Why aren't cell phones allowed to be used in aircraft?
8 votes

Cell networks require that cell towers be able to distinguish between signals coming from phones which are within the zones served by the towers, and those coming from phones in more distant zones. ...

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What is the purpose of the hole in the Cirrus SR22's parachute?
6 votes

In order for a parachute to move through the air, all of the air underneath it needs to move out of its way. If a concave round parachute didn't have any kind of hole in it, it would fill with a ...

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Why do jet engine igniters require huge voltages?
3 votes

If one passes current through a coil at low voltage and disconnects it suddenly, it will produce a voltage which is orders of magnitude higher unless current starts flowing again (the only reason ...

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Why is thrust inverse to speed in piston engines?
1 votes

Increasing the rotational speed of a piston engine will increase the number of power strokes per second. This will increase the power output up to a certain point, but marginal efficiency will go ...

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Why do planes need a roll motion?
1 votes

If a plane is moving e.g. north and one wants it to be moving northeast, one must apply an eastward force to the airplane. A plane has four kinds of forces acting upon it--thrust, drag (force ...

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Are wings any more efficient at creating lift, versus orienting the engine's thrust downwards?
1 votes

A major advantage a wing has versus an engine is that in typical use it will constantly get to encounter relatively undisturbed air. A downward-pointed engine would create an area of low pressure ...

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Could you encode data in a Black Box ping?
0 votes

Even if one started a search with many vessels whose equipment can detect nothing more than that a beacon exists somewhere within 16km, a ship that detected a beacon's signal could summon one or more ...

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