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
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