science
posted by paulie .
How many cars are there in a long freight train if it take the entire train 2 minutes to pass a station as it travels at 40 miles/hour? Each car is 50 feet long

40 miles/hr = 40*5280/60 = 3520 ft/min = 70.4 cars/min
140.8 cars pass in two minutes. 
As the train is travelling at 40 Miles per hour, in two minutes it will travel:
40 / 60 * 2 = 1.333 Miles.
There are 5280 feet in one mile, so that would make the train:
5280 * 1.334 = 7040 feet long
The cars are 50 feet long each, so that would make the train have:
7040 / 50 = 140.8 Cars Long.