Một toa tàu đang chuyển động theo chiều mũi tên. C...
Câu hỏi: Một toa tàu đang chuyển động theo chiều mũi tên. Chiếc lò xo dãn ra.
![](data:image/png;base64,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)
Khẳng định nào sau đây là đúng?
A. Toa tàu đang chạy chậm dần
B. Toa tàu đang chạy nhanh dần
C. Toa tàu đang chạy với vận tốc không đổi
D. Toa tàu đang phanh gấp
Câu hỏi trên thuộc đề trắc nghiệm
Ôn tập trắc nghiệm vật lý 10 chương 2: Động lực học chất điểm