A man is walking at 4 km/hr. A 180 m long train crosses him in 12 seconds while coming from the opposite direction. What is the speed of the train (in km/hr)?
50
Since the train and the man are moving in opposite directions, their relative speed is the sum of their individual speeds.
The train crosses the man in 12 seconds, covering a distance equal to the train's length, 180 m.
Relative speed \(= \frac{180}{12} = 15\) m/s.
Convert to km/hr: \(15 \times \frac{18}{5} = 54\) km/hr.
This relative speed equals (speed of train + speed of man): \(v_{\text{train}} + 4 = 54\).
Therefore, \(v_{\text{train}} = 54 - 4 = 50\) km/hr.
Hence, the speed of the train is 50 km/hr.
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Important Questions from Problem on Trains
A train is to cover 370 km at a uniform speed. After running 100 km, the train could run at a speed 5 km/h less than its normal speed due to some technical fault. The train got delayed by 36 minutes. What is the normal speed of the train, in km/h?
A train travelling at 36 km/h crosses a pole in 25 seconds. How much time (in seconds) will it take to cross a bridge 250 m long?
A train covers 450 km at a uniform speed. If the speed had been 5 km/h more, it would have taken 1 hour less to cover the same distance. How much time will it take to cover 315 km at its usual speed?
A train crosses a pole in 12 sec, and a bridge of length 170 m in 36 sec. Then the speed of the train is:
The ratio of the speeds of two trains is 2 : 7. If the first train runs 250 km in 5 hours, then the sum of the speeds (in km/h) of both the trains is:
