The distanced a train travels varies directly with the amount of time t that has elapsed since departure. If the train travels 475 miles in 9.5 hours, how many miles did the train travel after 4 hours?
We are given that the distance traveled varies directly with time elapsed. Let's call the distance traveled D and the time elapsed T. So we have:
D = kT
where k is the constant of variation. We can find the value of k by plugging in the values given in the problem:
475 = k(9.5)
Dividing both sides by 9.5, we get:
k = 475/9.5
k = 50
Now that we know k, we can use it to find the distance traveled after 4 hours:
D = 50(4)
D = 200
Therefore, the train traveled 200 miles after 4 hours.