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Một con lắc lò xo gồm vật m
1
(mỏng phẳng) có khối lợng 2kg và lò xo có độ cứng
k=100N/m đang dao động điều hoà trên mặt phẳng nằm ngang không ma sat với biên độ
A=5cm.Khi vật m
1
dến vị trí biên ngời ta đặt nhẹ lên nó một vật có khối lợng m
2
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ma sát giữa m
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và m
1
la 0,2; lấyg=10m/s
2.
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2
để nó không bị trợt trên m
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đợc đặt trên giá cố định nằm ngang dọc theo trục lò xo.Hệ số ma sát trợt giữa giá đỡ và vật
nhỏ là 0,01.Từ vị trí lò xo không biến dạng truyền cho vật vận tốc ban đầu 1m/s thì thấy con
lắc dao động tắt dần trong giới hạn đàn hồi của lò xo.độ lớn của lực đàn hồi cực đại của lò
xo trong quá trình dao động là:
A. 19,8N B.1,5N C.2,2N D.1,98N
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