a train running at the speed of 180 km hr crosses a 365 meter long platform in 21sec. what is the length of the train
180 km/hr = 50 m/s
the front of the train arrives at t=0.
The front of the train leaves the platform at t = 365/50 = 7.3
The back of the train whose length is x leaves the platform at t = 7.3 + x/50
So, solve for x in
7.3 + x/50 = 21
To find the length of the train, we need to use the formula:
Total distance = Length of the train + Length of the platform
The total distance the train travels is the speed multiplied by time, which is 180 km/hr * (21 sec / 3600 sec/hr) = 1.05 km.
Now we can calculate the length of the train:
Total distance - Length of the platform = Length of the train
1.05 km - 0.365 km = 0.685 km
Converting km to meters:
0.685 km * 1000 m/km = 685 meters
Therefore, the length of the train is 685 meters.
To find the length of the train, we can use the formula:
Length = (Speed × Time) - Platform Length
Given:
Speed = 180 km/hr
Platform Length = 365 meters
Time = 21 seconds
First, we need to convert the speed from km/hr to meters/second, as the time is given in seconds and the platform length is in meters. We know that 1 kilometer is equal to 1000 meters and 1 hour is equal to 3600 seconds.
Converting the speed:
180 km/hr × (1000 meters/1 kilometer) × (1 hour/3600 seconds) = 50 meters/second
Now we can substitute the values into the formula:
Length = (50 meters/second × 21 seconds) - 365 meters
Length = 1050 meters - 365 meters
Length = 685 meters
Therefore, the length of the train is 685 meters.