Trái đất 

de

123

1/5 giờ = 60 : 5 x 1 = 12 ( phút )

co le la vay 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điên tự nhận mk ngu  ☻☻☻☻

me =32 vif 8 nhan 4 =32

Độ cứng \(k_0=1N/cm=100N/m\)

Cắt lò xo thành 2 đoạn có độ cứng là \(k_1;k_2\) thì phải thỏa mãn điều kiện khi ghép nối tiếp 2 lò xo này lại ta được lò xo có độ cứng ban đầu. Do vậy ta có:

\(\dfrac{1}{k_0}=\dfrac{1}{k_1}+\dfrac{1}{k_2}\)

\(\Rightarrow \dfrac{1}{100}=\dfrac{1}{200}+\dfrac{1}{k_2}\)

\(\Rightarrow k_2=200N/m\)

LƯU Ý

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Mỗi thành viên được gửi tối đa 5 câu hỏi trong 1 ngày

Các câu hỏi không liên quan đến toán lớp 1 - 9 các bạn có thể gửi lên trang web h.vn để được giải đáp tốt hơn.

Còn lại số chiếc bút là

    80 - 10 = 70 ( chiếc )

Đáp số : 70 chiếc bút

X x 5 = 130 - 5

Xx5=125

x=125:5

x=25