Final answer:
To determine the length of the bridge, convert the train's speed to meters per second, calculate the distance covered while the train crosses the bridge, and subtract the length of the train. The length of the bridge is found to be 245 meters.
Step-by-step explanation:
To solve this problem, we need to calculate the length of the bridge that the train crosses. T
he speed of the train is given as 45 km/h, which we can convert to meters per second (m/s) by multiplying by 1000 (to get meters) and then dividing by 3600 (to get seconds).
Therefore, the speed in m/s is (45 * 1000) / 3600 = 12.5 m/s.
Since the train takes 30 seconds to cross the entire bridge, we can find the distance covered in this time by multiplying the speed of the train by the time taken:
distance = speed * time
= 12.5 m/s * 30 s
= 375 m.
This distance is the combined length of the train and the bridge.
As we know the length of the train is 130 m, we can subtract this from the total distance to find the bridge's length.
Therefore, the bridge's length = 375 m - 130
m = 245 m.
The correct answer to the length of the bridge is 245 meters (Option C).