A train 450 m long is moving on a straight track with a speed of 82.2 km/h. The engineer applies the brakes at a crossing, and later the last car passes the crossing with a speed of 17.1 km/h. Assuming constant acceleration, determine how long the train blocked the crossing. Disregard the width of the crossing. (in second)(adsbygoogle = window.adsbygoogle || []).push({});

I used the formula DeltaX = VoT + 1/2AT^2 where A= 0

450 = 82.2 km/hT --> T = 5.47

From here I am at a lost to if I have done it correctly so far or I been inputing it incorrectly. But I think the step is:

deltaX = 17.1 km/h(5.47)

Again I am not sure if it is correct or not. Please help me out on figuring what I'm doing wrong or if I am at the right track.

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# Homework Help: In need of help!

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