To trains of length 275 m and 320 m are running at the speed 36 km/hr and 54 km/hr respectively calculate the time taken to cross each other
a. when runs in opposite direction
b. when runs in same direction
Answers
Step-by-step explanation:
When a moving object having some length crosses an another moving object of some length, It travels the sum of distance of its own and the distance of another abject.
Let the length of the first train (L1) and the length of another train is (L2).
Total distance = L1+L2 = 140 + 160 = 300 meter.
But when an object with some speed passes an another moving object it travels with a relative speed of the objects.
In case of opposite direction their relative speed will be the sum of their speed (S1 + S2) km/hr.
Speed of the first train (S1) = 60km/he and the speed of the another train (S2) = 40km/hr.
So relative speed of both the trains will be (60+40) km/hr or 100 km/hr or (100*5)/18 m/s or 500/18 or 250/9 m/s
By using basic formula of time speed and distance
Time = distance/speed
Time = (300)/(250/9) or 2700/250 or 54/5 or 10.8 seconds