[題目] 關於彈簧的作用力問題
[來源] 考卷
[題目] 兩矩形方塊A、B質量均為m,疊放在一個鉛直放置的彈簧上,今用一鉛直
向下的力F壓物塊A(仍在彈性限度內),若突然撤去F,此時A對B的作用力大小
為何?
□A
□B
—
∣
∣ 彈簧
∣
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[瓶頸] 設A、B間的作用力為f,則A受到B往上的力f,自己本身的重力
兩者合力對A造成的加速度應為(f-mg)/m
而A的加速度又等於A、B兩塊一起受F和兩者合力造成的加速度(F-2mg)/2m
(f-mg)/m=(F-2mg)/2m
解得f=F/2
可是答案是(F/2)+mg
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推
12/17 22:40, , 1F
12/17 22:40, 1F
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12/17 22:46, , 2F
12/17 22:46, 2F
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12/17 22:47, , 3F
12/17 22:47, 3F
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12/17 22:47, , 4F
12/17 22:47, 4F
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12/17 22:51, , 5F
12/17 22:51, 5F
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12/17 22:52, , 6F
12/17 22:52, 6F
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12/17 22:52, , 7F
12/17 22:52, 7F
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12/17 22:53, , 8F
12/17 22:53, 8F
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12/17 22:53, , 9F
12/17 22:53, 9F
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12/17 22:53, , 10F
12/17 22:53, 10F
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12/17 22:57, , 11F
12/17 22:57, 11F
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12/17 23:01, , 12F
12/17 23:01, 12F
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12/17 23:06, , 13F
12/17 23:06, 13F
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08/13 15:59, , 14F
08/13 15:59, 14F
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09/17 13:59, , 15F
09/17 13:59, 15F
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11/09 12:10, , 16F
11/09 12:10, 16F
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07/06 22:45,
4年前
, 17F
07/06 22:45, 17F