làm giúp mình với!!! bài 1:. Một người kéo một vật từ giếng sâu 8m lên đều trong 20s. Người ấy phải dùng một lực F = 180N. Tính công và công suất của người kéo. bài 2:. : Nước đang chảy từ trên cao xuống, so với mặt đất thì nước có dạng cơ năng nào ? Vì sao ?. Cơ năng của nước càng lớn trong điều kiện nào ? bài 3:Một công nhân khuân vác trong 2 giờ được 48 thùng hàng, mỗi thùng hàng phải tốn một công là 15000J. Tính công suất của người công nhân đó? MÌNH HỨA SẼ VOTE 5 VÀ CHỌN LÀ CÂU TRẢ LỜI HAY NHẤT!!FIGHTING

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