A train is moving east at a speed of 5 ms-1. A bullet fired westwards with a velocity of 10 ms-1 crosses the train in 8s. The length of the train is:
Correct answer: A. 120 m
- A. 120 m
- B. 60 m
- C. 30 m
- D. 15 m
Explanation
To determine the length of the train, first calculate the relative velocity of the bullet with respect to the train. Since the train is moving east at 5 m/s and the bullet is fired westwards at 10 m/s, their relative velocity is 5 m/s + 10 m/s = 15 m/s (since they are moving in opposite directions). The length of the train is then the product of this relative velocity and the time it takes for the bullet to cross the train: Length = 15 m/s * 8 s = 120 m. Therefore, the correct answer is 120 m. The other options are incorrect as they do not accurately apply the relative velocity and time to determine the train's length.
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