Đáp án:
p=4mv
Giải thích các bước giải:
ta có công thức động lượng : p=mv
mà tăng khối lượng và vận tốc lên 2 lần thì => p=2m2v=>p=4mv
Không đổi
Có p=m×v
Mà m÷2 và v×2
Suy ra p= m÷2×v×2=m×v
một cần cẩu nâng vật có khối lượng 2 tấn làm cho vật chuyển động nhanh dần đều theo phương thẳng đứng lên cao 12,5 m với gia tốc 1 m trên giây bình lấy g =10 m/s² . Hãy tính công mà cần cẩu thực hiện và công suất trung bình của cần cậu ấy
Một động cơ có công suất tiêu thụ bằng 5kW kéo một vật có trọng lượng 12kNlên cao 30 m theo phương thẳng đứng trong thời gian 90 giây với vận tốc không đổi khi hiệu suất của động cơ này ?
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Cho biểu thức P= cănx-1/x+8. Tính GTLN của biểu thứcP
Hoà tan m gam Cu vào 80ml dd hno3 loãng 1M thoát ra V lít khí và dung dịch B tính m và v và m gam muối sau khi cô cạn dd B . Nhiệt phân muối lên thì thu được m gam
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Cho mình hỏi. Câu tạo của phép so sánh là sao ạ.
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