SOLUTION: a train crosses a highway travelling North at 60mph. One hour later, a car travelling East at 45 miles per hour on the highway crosses the train track. To the nearest 0.1 hour, aft
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Question 719546: a train crosses a highway travelling North at 60mph. One hour later, a car travelling East at 45 miles per hour on the highway crosses the train track. To the nearest 0.1 hour, after how long will the train and car be 100 miles apart? Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! train has traveled 60 when the car is crossing the track
After x hours car will be at a distance of 45x miles
The train will be at a distance of 60x+60 .
they are at right angles with respect to the intersection
(60x+60)^2+(45x)^2=100^2
3600x^2+7200x+3600+2025x^2=10000
5625x^2+7200x-6400=0
factorize.
we get two values x=0.6 OR -1.88
ignore negative value.
so 0.6 hours
