Concept explainers
You’re an investigator for the National Transportation Safety Board, examining a subway accident in which a train going at 80 km/h collided with a slower train traveling in the same direction at 25 km/h. Your job is to determine the relative speed of the collision, to help establish new crash standards. The faster train’s “black box” shows that its brakes were applied and it began slowing at the rate of 2.1 m/s2 when it was 50 m from the slower train, while the slower train continued at constant speed. What do you report?
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