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tranghvgfd
2 năm trước
Cho một vật rắn chuyển động trên đường nằm ngang. Tính công cản và công phát động khi S = 10 m trong 2 trường hợp sau : a) Vật chuyển động thẳng đều. b) Vật bắt đầu chuyển động nhanh dần đều và đạt được vận tốc 4 m/s. Biết hệ số ma sát là 0,1 và vật đó có khối lượng là 2kg.
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