Question 632998
A train is passing a platform 50 metres long.
 It takes 20 seconds from the time the front of the engine reached the start
 of the platform till the last carriage past the end of the platform.
 If the average speed of the train was 50km/h, how long was the train?
:
convert 50 km/h to meters/sec
{{{(50*1000)/3600}}} = 13.889 m/sec
:
Let t = length of the train
the back of the train travels an additional 50 m to the end of the platform
 {{{(t+50)/13.889}}} = 20
 t + 50 = 20*13.889
 t + 50 = 277.8
 t = 277.8 - 50
 t = 227.8 meters is the length of the train