a man walking at an average speed of 4 mph alongside a railroad track. A frieght train, going in the same direction at an average speed of 30 mph, requires 5 seconds to pass the man. How long is the Freight train? give your answer in feet.
(the answer is 190.67 ft long)
2007-09-05 16:56:51 · 2 answers · asked by Richard C 1 in Science & Mathematics ➔ Mathematics
the answer is in the back of the book
2007-09-05 17:09:18 · update #1
The speed of the train can be considered 26mph and the person standing still, that makes it more simple (30-4=26). 5 seconds divided by 3600 (seconds to minutes to hours) gives you .001388 hours. Multiply that by 26mph and you have .03611 miles (the length of the train). This is 210.66 feet. I think your answer might be wrong? Or reread the question and make sure the #'s are right.
2007-09-05 17:07:31 · answer #1 · answered by Matt C 1 · 0⤊ 0⤋
A calculus problem?
If you draw a diagram of the train just as the front of the train lines up with the man and then 5 seconds later, where the end of the train lines up with the man, the length of the train+distance man travels in passing time=
speed* passing time SO................
LT+ 4*(88/60)*5 = 30*(88/60)*5.
The term 88/60 converts mph to fps.
Then LT = 26*60*5/88
2007-09-06 00:10:07 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋