Khi lắp đặt đường ray xe lửa ở 100 , chỗ mối nối giữ hai thanh ray người ta chừa một khoảng hở kỹ thuật là 0,8 cm và ở nhiệt độ này mỗi thanh ray có chi u dài là 10 m. Vào mùa hè khi nhiệt độ lên đến 42 0C thì mỗi thanh ray sẽ dài thêm bao nhiêu cm? Khoảng hở kỹ thuật chỗ mối nối giữ hai thanh ray luc đó có còn đủ lớn để các thanh ray dễ dàng nở ra hay không, vì sao? (Cho biết với 1m thanh ray khi nhiệt độ tăng thê 10C , thì chieu dài thanh ray sẽ tăng thêm là 0,0012 cm) Em đang cần gấp mọi người giúp em nhé, em cảm ơn

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