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egrr10
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Homework Statement
The engineer of a passenger train traveling at 25.0 m/s sights a freight train whose caboose is 200 m ahead on the same track. The freight train is traveling at 15.0 m/s in the same direction as the passenger train. The engineer of the passenger train immediately applies the brakes, causing a constant acceleration of 0.100 m/s^2, while the freight train continues with constant speed. Take x=0 at the location of the front of the passenger train when the engineer applies the brakes. Find the deceleration of the passenger needed in order to avoid collision.
Homework Equations
Vx^2=Vox^2 + 2ax(x-xo)
The Attempt at a Solution
I'm using V of the freight train as the final and the V of the passenger as the initial and 200m as the distance.
Rearranging the equation,
(15^2-25^2)/(200*2)=-1m/s^2
Or do I use the relative velocity between passenger train and freight train 10m/s (25-15) as the initial and 0m/s (coming to a complete stop) as the final.
(0^2-10^2)/(200*2)=-0.25m/s^2