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hannah2709
2 năm trước
Một tên lửa có khối lượng tổng cộng 100 tấn đang bay với vận tốc 200m/s đối với trái đất thì phụt tức thời ra phía sau 20 tấn khí với vận tốc 500m/s đối với tên lửa . Tính vận tốc của tên lửa sau khi phụt khí .
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