A train of length 150m is going north with a speed of 10ms-1. A parrot flies 5ms-1 toward the south parallel to the railway line. The time taken by the parrot to cross the train is:
Correct answer: B. 10 s
- A. 8 s
- B. 10 s
- C. 12 s
- D. 15 s
Explanation
When two objects are traveling in opposite directions the relative velocity adds up. So, the velocity of the train relative to the bird = 5 + 10 = 15ms-1 Time = distance/speed = 150/15 = 10ms-1
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