Friday 18 April 2008

Zeus? =.=

最近雨下不停,
刚刚在车上昏昏欲睡时被一个很大声的雷声吓到,
就干脆不睡了。

看着一道道的闪电,耳边又传来阵阵的雷声,
想起之前有看过说其实你是可以算到闪电的发生是在你的头顶上的几公里处发生的。
忘了是怎样的一个公式,就自己随便弄一个出来。

d=v X t
take ds as distant traveled by sound,
dl as distant traveled by light

let T1=the delay between lightning and thunder

ds=dl
vs X (t+T1) = vl X t
1 + T1/t = vl/vs
t = vsT1/(vl-vs)

d=v X t
d=vl X vsT1/(vl-vs)

where,
vl=3X10^8m/s
vs=343m/s

since vs is so small compared to vl,
it can be ignored in the equation of vl-vs

in which, the equation will the become

d=vl X vsT1/(vl)
d=vsT1
d=343T1 (m)

Hence,
要得到那些++--的东西是在你的头上方多远处跳动,
在你看到闪电的那一瞬间,就开始数秒,
把你得到的乘声音的速度,也就是大概343,
得到的答案是in meter


It did took me quite a long time to complete
太久没用脑袋真的会生锈,
有什么错的地方的话,
欢迎纠正。

2 comments:

Unknown said...

chim
0.o

G said...

lol
Simple calculation only lah