A 150m long train is moving with uniform velocity of 45km/hr.The time taken by the train to cross a bridge of length 850 meters is
d = 150 + 850 = 1000m. = 1 km.
d = V*t
1 = 45*t
t = 0.0222h,
t = 0.0222h * 3600s/h = 80 s.
To find the time taken by the train to cross the bridge, we need to first calculate the relative speed of the train with respect to the bridge.
The speed of the train is given as 45 km/hr, which can be converted to meters per second (m/s) by the following conversion:
1 km/hr = 1000/3600 m/s
So, the speed of the train is:
45 km/hr * (1000/3600) m/s = 12.5 m/s
Now, when the train is crossing the bridge, it needs to travel an extra distance equal to the length of the bridge. Therefore, the total distance to be covered by the train is the sum of the length of the train and the length of the bridge:
Total distance = length of train + length of bridge
Total distance = 150 m + 850 m
Total distance = 1000 m
Now, we can calculate the time taken by the train to cover this total distance at its speed of 12.5 m/s using the formula:
Time = Distance / Speed
Time = 1000 m / 12.5 m/s
Time = 80 seconds
Therefore, the time taken by the train to cross the bridge is 80 seconds.