【英語時間】Do coins falling from tall buildings kill?
發佈時間：20:44 2021-03-15
We know that things falling from tall buildings can hurt or even kill people, because the thing will accelerate as it falls, making it exert a larger force on an object it touches on the ground. That is why some say that a coin, though very light, can kill people if it falls from a very tall building. Fortunately, that is not true.
Yes, in theory, an object travels faster and faster when it falls to the ground. But that is only true in a vacuum. If there is air, like here on Earth, the air resistance will soon stop the increase in speed, which prevents the coin from being harmful to us.
However, do not drop things from a building because they may be much heavier than a coin and can still hurt or kill people!
Do ostriches bury heads to avoid danger?
We often say that people who avoid problems are like ostriches, because these animals bury their heads in the sand in order to avoid danger. But that is not true at all!
Ostriches have very sharp eyes and can walk very fast, up to 70 kilometres per hour. Therefore, when they see danger, like a lion coming, they can simply escape.
Why then is there such a myth? Probably because ostriches sometimes lower their heads to swallow sand and small stones to help digest their food.
Also, ostriches lay their eggs in a hole in the sand, and they need to lower their heads to turn the eggs sometimes, and we think (wrongly) that they are burying their heads.
Vocabulary
accelerate (v) 加速
exert (v) 施加
vacuum (n) 真空
resistance (n) 阻力
ostrich (n) 駝鳥
myth (n) 錯誤觀念
