A train 140 meters long passes a pedestrian walking at 4 km/h in the same direction in 12 seconds. What is the speed of the train? MCQ with Answer and Explanation
A train 140 meters long passes a pedestrian walking at 4 km/h in the same direction in 12 seconds. What is the speed of the train?
A. 46 km/h
B. 50 km/h
C. 54 km/h
D. 42 km/h
Answer: Option A
Solution (By JKSSB Mock Tests)
Relative speed = 140 / 12 = 35/3 m/s = (35/3) * (18/5) = 42 km/h. Since both walk/move in the same direction, Relative Speed = Speed of train - Speed of pedestrian => 42 = Speed of train - 4 => Speed of train = 46 km/h.
A commuter departs from outpost A at 5:00 AM at 25 km/h. Another starts from A at 7:00 AM at 35 km/h tracking along the same direction corridor. At what distance away from A will they intercept?
Explanation:
By 7:00 AM, the first commuter tracks for 2 hours, covering 25 * 2 = 50 km. Relative speed index = 35 - 25 = 10 km/h. Time to intercept = 50 / 10 = 5 hours. Distance path from point A = Speed of second commuter * Intercept Time = 35 * 5 = 175 km.
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