http://i137.photobucket.com/albums/q224/gerrard1023/force.jpg
請附加解釋!!!!
超難力學問題
2007-04-01 2:40 am
回答 (3)
2007-04-02 5:13 am
✔ 最佳答案
Let F = Net force act on the balloon after the string brokenF = ma,
= (50÷1000)(2)
= 0.1N
The ball is at rest before the string is broken.
i.e. The upward force – the downward force = 0
F – T = 0
F = T
T = 0.1N
∴The answer is B. 0.1N.
2007-04-02 18:47:08 補充：
thx呀...估唔到你會揀我呀~
2007-04-01 3:03 am
before break: T+mg=F (F bouyant force)
after: F-mg=ma=0.05x2=0.1
so T=0.1N
after: F-mg=ma=0.05x2=0.1
so T=0.1N
2007-04-01 2:51 am
answer係咪d阿..
因為佢向上飛,acceleration係2ms^(-2),但係個gravitaional acceleration向下係10ms^(-2),咁即係o個舊野ge total acceleration係12ms^(-2),所以個波ge total force係0.6ms^(-2)(f=ma)
因為newton's third law,action=reaction,所以個tension係0.6..對嗎?
因為佢向上飛,acceleration係2ms^(-2),但係個gravitaional acceleration向下係10ms^(-2),咁即係o個舊野ge total acceleration係12ms^(-2),所以個波ge total force係0.6ms^(-2)(f=ma)
因為newton's third law,action=reaction,所以個tension係0.6..對嗎?
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