| [ sciEncE ] in KIDS 글 쓴 이(By): mkjung (Fiat Pork) 날 짜 (Date): 2000년 10월 5일 목요일 오전 08시 11분 17초 제 목(Title): Re: 금성의 기압 통계공부하시는 모씨 께서 이 평균속력이 탈출속도의 0.2배 정도 일때 맥스웰 분포에 의거, 원래 대기양의 반정도가 되는 시간을 계산해 주시리라 믿습니다. 나무 심는 거보다는 이게 더 재미있으리라 보는데요. =========== man give me a break. it can not be computed without the input/output modeling of the atmosphere. but since i am boring. i will do it with little assumption. ^^ maxwell distribtuion is nothing more than gaussian distribtuion. also even if the molecules have the escape velocity, all of them will not escape because if they are moving downward with the escape velocity, they will not escape but bounce around. so if X = 0.2 \mu , right hand tail of the gaussian distribtuion that is bigger than \mu is less than 5%. each time you are taking out 5% of atmosphere and want to find the time of the half life. assuming that 5% evaporation takes about 1 thousand years. what is the half life? hm... let a_n = 0.95*a_{n-1} then a_n = 0.95^n a_0 with a_0 = 1 so 0.95^n = 0.5 n = ln 0.5/ln 0.95 so my proud estimation is 1000* ln 0.5/ln 0.95 years. kiki... easy. ^^ |