In 10 seconds, a 125-meter-long train passes a man jogging at 5 km/hr in the same direction as the train. The train's top speed is
A. 45 km/hr
B. 50 km/hr
C. 54 km/hr
D. 55 km/hr
Answer:B
In 10 seconds, a 125-meter-long train passes a man jogging at 5 km/hr in the same direction as the train. The train's top speed is
A. 45 km/hr B. 50 km/hr C. 54 km/hr D. 55 km/hr
Explanation: Train speed in relation to man = 125/10 m/sec= 25/2 m/sec.= 25/2 x 18/5 km/hr,45 km/hr is a speed of 45 km/hr.Let's say the train's speed is x km/hr. The relative speed is then equal to (x - 5) km/hr, x - 5 km/hr = 45, x = 50 km/hr