새들은 전기줄에 앉아 있는데 감전 사고가 일어나지 않을까?
출처 : youtu.be/rtnmCf2QFTc
배경 : 산책을 하던중 아들의 질문, 새들은 왜 감전이 안되고 전기줄에 앉아 있지? 답을 바로 못해주었다. 공부해서 아들에게 전해줘야지..
1. Electrical current (electron들의 이동) 때문이다.
2. Electrons 은 발전소 (power station)-전선주 (the mains)-가정 (house)-전선주 로 이동 : "closed loop"
3. Closed loop : 전기의 흐름에 필요하다
4. 전기는 electrical potential 이 높은곳에서 낮은 곳으로 이동
5. 새는 하나의 전기줄 두 다리를 이용해서 앉기 때문에 "same electrical potential" 임 : 전기 이동 없음.
6. 하지만, 새도 두개의 전기줄을 우연히 동시에 접촉하게 되면 순간적인 electrical potential 발생으로 감전사 발생함 **
7. 전선주의 기둥(Pole) 은 땅에 박혀 있기 때문에 지상에 두발을 두고 있는 사람이 전선을 만지면 바로 전기가 통하게 됨
8. 전기 작업을 하는 작업자들은 절연체 (insulation) 이용하고, 혹은 헬리콥터를 이용해서 두발을 대지에 닿지 않게 해서 작업함
- 단어와 예문은 "네이버 사전" 과 "learnersdictionary.com 를 이용함.
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Would you ever touch a live electrical wire?
Of course not. Because it is likely to kill you.
How come birds can sit unruffled on high-voltage power lines?
What magical ability do they have to withstand such contact?
To understand that, we must first understand electrical current.
Electrical current is the movement of electrons.
These electrons travel from the power station to your house through the mains.
They then move through the power lines through your electronic devices and eventually return to the mains.
This process takes place in a closed loop.
This closed loop is necessary in order for electricity to flow
in order to move
electrons also require a difference in electrical potential
simply put
electrons move from a higher electrical potential to a lower one
Imagine a bunch of balls on top of the hill!
if they are not blocked, they will roll down any path that becomes available
This is similar to how electrons move from one electrical potential to another.
But when a bird sits on a wire
both of its feet are at the same electrical potential
so the electrons therefore have no reason to flow through the bird's body
No moving electrons means no electric current
the bird is safe unless it suddenly touches another electrical wire, especially one with a different electrical potential
if it does this, it opens a path for the electrons to flow
a path for electrons to move through its body
It is also dangerous for birds to sit on the wooden poles, supporting the wires
This pole is buried in the ground so it has a low electrical potential
if a bird were to sit on that pole and simultaneously touch a wire
the current would once more flow from the high potential wire
through the bird's body and into the low potential ground
This is the same reason why it is dangerous for humans to touch live wires
Since we are almost always in contact with the ground
our bodies serve as a conductor for current to move from an area of high potential like a wire
to an area of lower potential, the floor.
Our bodies make excellent electrical conductors and the result is that we get zapped.
This is why workers repairing live electrical wires use insulating materials such as rubber in their clothing and equipment
Even their bucket trucks are properly insulated
these insulating materials do not conduct electricity
so the electrons are blocked from flowing
workers who repair power lines also sometimes work
while hanging from a helicopter, ensuring they are not touching the ground
They still need to make sure they only touch one wire at a time though
This is why the job of electrical repair remains one of the most dangerous around
which leads to our conclusion
it may be safe for birds to sit on electrical wires but humans should stay far away
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unruffled : 침착한 (unperturbed), 냉정을 잃지 않는 He remained unruffled by their accusations (비난). the mains : (한 건물지역으로 들어가는 수도,가스,전기 공급이 시작되는) 본선 The house is not yet connected to the mains. Turn off the water at the mains. zap : to hit (someone or something) with electricity Lightning zapped [=struck] the tree. = The tree was zapped by lightning. She won't work with the wiring because she's afraid of getting zapped. [=shocked, electrocuted] |
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