Two trains of lengths 160 meters and 140 meters are moving in opposite directions at 55 km/h and 65 km/h, respectively. Find the time taken by them to cross each other completely.
9 seconds
When two trains move in opposite directions, their relative speed is the sum of their speeds.
Relative speed \(= 55 + 65 = 120\) km/h.
Convert to m/s: \(120 \times \frac{5}{18} = \frac{100}{3}\) m/s.
Total distance to be covered while crossing \(= 160 + 140 = 300\) m.
Time \(= \frac{300}{\frac{100}{3}} = 300 \times \frac{3}{100} = 9\) seconds.
Hence, the trains take 9 seconds to cross each other completely.
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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:
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