求救~物理好難
 

In a certain library the first shelf is 12.0cm off the ground,and the remaining 4 shelves are each spaced 33.0cm above the previous one.If the average book has a mass of 1.60kg with a height of 22.0cm, and an average shelf holds 25 books(standing vertically), how much work is required to fill this bookshelf from scratch, assuming the book are all laying flat on the floor to start?

答案只要接近1740焦耳都算對
請各位大大不另賜教~謝謝

我弄出來是1744.40J:)
設G=9.8

1.6 X 9.8 X (0.12 +0.11 ) X 25 -->first shelf
1.6 X 9.8 X (0.12 + 0.33 + 0.11 ) X 25 --> second shelf
....
最後加起來=1744.40J


0.11 是 0.22 (average height)/2

已經兩年沒碰過物理
錯了別打我:p :p

嗯~原來如此
兩年沒碰物裡竟然還解的出來
Gladiac15GHz 您太強了
感謝您的大力相助
謝謝

臥虎藏龍,

好羨慕...