Question

An automobile traveling 95 km/h overtakes a 1.80 km -long train traveling in the same direction on a track parallel to the road. If the train's speed is 75 km/h, how long does it take the car to pass it? How far will the car have traveled in this time? How long does it take the car to pass the train if the car and train are traveling in opposite directions? How far will the car have traveled in this time?

Answer 1

The automobile is traveling 20 km/h faster than the train. Thus, it will cover extra 1.8 km in 1.8/20 = 0.09 hours.

Since d = rt, the car will have traveled 0.09*95 = 8.55 km in this time.
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Now, since the automobile and train are traveling towards each other, we have to add their speeds. 95 + 75 = 170 km/hr. This means the distance between the end of the train and the automobile is closing at 170 km/hr

1.8/170 = 0.0106 hr.

Since d = rt, the car will have traveled 0.0106*95 = 1.007 km in this time.