Freight Train Engineers - 4,000-Ton Train Coasting Distance at 70 mph

Train math question Hi train people I'm working on a story about trains and was trying to figure out something. I'd like to illustrate how efficient freight by rail is and had a line like "The momentum of a train is so much that if you stopped powering a 4,000 ton train going seventy miles an hour on flat land that train would continue to roll for \\\_\\\_\\\_\_." Can anyone help me with this hypothetical? I'm not sure how to calculate it, but I feel like, because trains weigh so much, they're roll for a long time ha, very scientific i know -thanks!