子彈以500ms^-1的速率射向一道木牆
它在牆壁內的匀減速度是800000ms^-2。
子彈冇穿木牆,牆有幾厚？？
Anwser：15.8 cm
物理力學一問
2007-03-07 9:16 pm
回答 (2)
2007-03-07 9:25 pm
✔ 最佳答案
Assume there is no frictions,then Change of Kinetic Energy of the bullet=Work done added on the borad
1/2mv^2=Fd
1/2mv^2=mad
1/2(500)^2=800000 d
d=0.15625 (m)=15.625cm
in order to not passing through the wall, the thickness must be greater than 15.625cm
2007-03-08 12:14 am
子彈以500ms^-1的速率射向一道木牆
它在牆壁內的匀減速度是800000ms^-2。
子彈冇穿木牆,牆有幾厚？？
by
s = v^2 - u^2 / 2a
s = -500^2 / -2(800000)
s = 0.15625m
so,
s = 15.6cm
它在牆壁內的匀減速度是800000ms^-2。
子彈冇穿木牆,牆有幾厚？？
by
s = v^2 - u^2 / 2a
s = -500^2 / -2(800000)
s = 0.15625m
so,
s = 15.6cm
參考: eason mensa
收錄日期: 2021-04-13 17:40:10
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070307000051KK01106