問數

一個短跑手,順風跑90米,用了10秒,狂同樣的風速下,逆風跑了70米也用了10秒.那麼在無風的時侯跑一百米,需時幾秒?

13 1/3秒

[quote][b]原帖由 [i]kelvinNg[/i] 於 2008-10-8 09:05 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271290][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
13 1/3秒 [/quote]
請列式:em46::clown:

[quote][b]原帖由 [i]`乜叉.[/i] 於 2008-10-8 09:07 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271296][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]

請列式:em46::clown: [/quote]
好想打你]



let x be the speed of the athlete
    y be the speed of wind

x+y=90m/10s...........1
x-y=70m/10s............2

1+2
2x=15
x=7.5


∴the speed of athlete is 7.5m/s
∴the second the athlete use when windless is 100/7.5=13 1/3

[quote][b]原帖由 [i]kelvinNg[/i] 於 2008-10-8 09:14 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271305][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]

好想打你]



let x be the speed of the athlete
    y be the speed of wind

x+y=90m/10s...........1
x-y=70m/10s............2

1+2
2x=15
x=7.5


∴the speed of athlete is 7.5m/s
∴ ... [/quote]
唔好打我呀:em35:

回覆 #5 `乜叉. 的帖子

我又要打!!!:em28:

[quote][b]原帖由 [i]`乜Q]'[/i] 於 2008-10-8 09:47 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271337][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
我又要打!!!:em28: [/quote]
打你個頭.

你真係問左^_^

[quote][b]原帖由 [i]夏雪~[/i] 於 2008-10-8 10:25 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271396][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
你真係問左^_^ [/quote]
係..
miss話係12.5s...

回覆 #9 `乜叉. 的帖子

..........
唔知答你咩好+3+
因為我對maths真係無D認識-_-

[quote][b]原帖由 [i]夏雪~[/i] 於 2008-10-8 10:29 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271408][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
..........
唔知答你咩好+3+
因為我對maths真係無D認識-_- [/quote]
你該答我...哦"//係咩?

回覆 #11 `乜叉. 的帖子

嗯^_^
知道了*v*

[quote][b]原帖由 [i]夏雪~[/i] 於 2008-10-8 10:32 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271416][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
嗯^_^
知道了*v* [/quote]
這就對了.

回覆 #7 `乜叉. 的帖子

打你果個呀！！你個大dd:P

[quote][b]原帖由 [i]`乜Q]'[/i] 於 2008-10-8 10:34 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271419][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
打你果個呀！！你個大dd:P [/quote]
你個大dd<<<<???

計錯= =||

[quote][b]原帖由 [i]奇拿[/i] 於 2008-10-8 10:35 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=2#pid271422][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
計錯= =|| [/quote]
乜水計錯..

kevin囉= =

[quote][b]原帖由 [i]奇拿[/i] 於 2008-10-8 10:37 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=2#pid271426][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
kevin囉= = [/quote]
你嘅做法係點呀- -?

[quote][b]原帖由 [i]kelvinNg[/i] 於 2008-10-8 09:14 PM 發表。&nbsp;[/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271305][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]

好想打你]



let x be the speed of the athlete
    y be the speed of wind

x+y=90m/10s...........1
x-y=70m/10s............2

1+2
2x=15
x=7.5


∴the speed of athlete is 7.5m/s
∴ ... [/quote]
好屈機啊@@

[quote][b]原帖由 [i]`乜叉.[/i] 於 2008-10-8 10:27 PM 發表。&nbsp;[/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=1#pid271403][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]

係..
miss話係12.5s... [/quote]
我發左雞瘟
16/2=7.5 = =
so100/8=12.5

你地到底講咩?

[quote][b]原帖由 [i]jackylai02[/i] 於 2008-11-8 11:30 PM 發表。 [/b][url=http://forum.eyankit.com/viewthread.php?tid=28857&page=2#pid289365][img]http://forum.eyankit.com/images/common/back.gif[/img][/url]
你地到底講咩? [/quote]
睇#1

諗下諗下要向量計