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vothithanhy.10a1
2 năm trước
Một vật khối lượng 4kg đang chuyển động với vận tốc 3m/s trên sàn nằm ngang. Tác dụng lực F không đổi song song với mặt sàn, làm tăng tốc vật. Đi được 10m thì vận tốc là 5m/s. Lực ma sát không đổi và có độ lớn 4N. Lấy g=10m/s^. a) Tính độ biến thiên động năng của vật b) Tính công của lực F và độ lớn của F.
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