These problems are commonly asked in competitive exams and here we are going to learn how to solve those common problems.
When a train crosses any stationary body or platform, the total distance travelled by the train will be the length of the train.
How to calculate speed of the train
Suppose the train is covering 1000 meters in 10 minutes then do will you calculate its speed. If we are calculating speed in minutes the we will have to find speed in 1 minute. If we are calculating speed in seconds then we will have to find speed in 1 second. If we are calculating speed in hours then we will have to calculate speed in 1 hour
Therefore speed of the train will be 100 meters per minute. So we can come to formula of speed.
If we divide distance by time, we get the speed
1000 meter / 10 minutes = 100 meters/min
As we know that 1000 meter is 1 km and 10 minute is 0.16 hour therefore it speed in km / hr will be
1 km / 0.16 = 6.25 km/hr
Sample Question
A train is running at the speed of 60km/hr and it crosses a pole in 9 seconds then what is the length of the train?
Since hour speed is in km per hour we will have to first convert it to meter/second
1 km = 1000 meters
1 hour = 60×60 seconds
So 1km/1hour = 1000/(60*60) = 0.27
(1000/(60*60) ) x 60 =16.6 meter / second is the speed of train in meter/second
now since train is taking 9 seconds so the total distance covered by the train will be
16.6 x 9 = 150 meters
Speed = Distanc/Time
Distance = Speed X Time
Time = Distance / Speed