因為無displacement , 所以用唔到work done 條式,唔識計
thx
更新1:
嗯, 謝謝了 但 work 不是沒有方向嗎 如果向下move 1m ,向上move 1m work done 不是 2mgh嗎?
energy 問題
2007-12-19 3:23 pm
想問下hold 住一個10N 的object 需要幾多energy
因為無displacement , 所以用唔到work done 條式,唔識計
thx
因為無displacement , 所以用唔到work done 條式,唔識計
thx
回答 (1)
2007-12-19 8:35 pm
✔ 最佳答案
No energy is need. As you stated no displacement, so there is no work is done.If you put an object on the table, it will stay still. When you are holding the object and you felt tired due to your muscles are being relax and contact, energy is losing here.
Taking this as an example, the 10N object is move down by 1m and then up by 1m with CONSTANT VELOCITY. The total work done is zero, by energy is used. When moving down it takes 10J and the same when it was moving up.
Your muscle are doing the similar case as the above, but it is relaxing and contacting.
收錄日期: 2021-04-23 17:33:31
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