<PRE><B>Question 635417</B>
Two trains travelling with speed 60 km/hr and 80km/hr are headed towards one another along a straight level track. when they are two km apart both the locopilots apply their breaks.if the breaks decelerates each train at the rate of 1.7m/s^2 determine weather there is a colliosion?
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The combined speed = 140 km/hr = 38.889 m/sec
The combined acceleration (of the brakes) is 3.4 m/sec/sec
v = a*t
t = v/a = 38.889/3.4 =~ 11.438 seconds
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s = (1/2)at^2 = (1/2)*3.4*11.438^2
s = 222.4 meters, less than 2 km, no collision
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