1 phy question

我頭先用個磅 磅下自己幾重= =

第1次 我放左張瓦通紙係個磅下面

102磅

第2次 我拎走左張紙(即係個磅下面咩都無)

103.5

我重覆試過好多次

都係無紙個個既result > 有紙個個

而且唔係淨係今日,

留意左e個問題好耐,不過無諗個點解

我想問個source of error係咩?

Update:

個balance得出的result係depends on force exerts on it.

if force acts on the balance increases,normal reaction acts on you increases,so the reading increases.

Update 2:

你既意思

係咪即係話"force acts on balance by you"唔係全部acts左落個balance到

有d acts 左落張紙到,所以

force acts on the paper + balance by you= force acts on paper by you+ force acts on balance by you(廢話= =)

而你既weight 係fixed,所以force acts on balance decreases

所以,normal reaction acts on u decreases,即係個reading decreases?

Update 3:

如果係咁,我有問題想問

If balance下面咩都無,得地板

force acts on space under you by you

= force acts on balance by you + force acts on the floor by you

因為有air trapped in the paper,所以瓦通紙會吸左d力,咁個地板會唔會吸左d力?

1 Answer

Rating
  • 8 years ago
    Favorite Answer

    因為瓦通紙中間有空間,當你站上去時,空間被你的重量而變得高密度,瓦通紙吸去你加 上的部份 重量,所以 看上去輕一點,但人和瓦通紙 的質量沒變,只是重量變輕。

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