Train – Velocity question
Amit always walked across the railroad bridge on his way to school. One day, Amit was one-fourth of the way across the bridge when he heard a train approaching from behind him. It was exactly one bridge-length away from him. Which direction should he run...back or forward?
I'm not sure of the
I'm not sure of the answer... with no details given regarding the speed of either the train or the boy's run... i feel the answer depends on on the relative speeds...
Incognito, kindly throw light with your explanation...
sure looks like a physics
sure looks like a physics problem to me , speed of sound , speed of train , speed while running !!!
Looks like inequality
Suppose the boy speed is: x
the train speed is: z
the bridge length is: y
Distance covered by boy if he travels towards the train: y/4
Distance covered by the boy if he travels opposite the train 3y/4
Let t1 be the time if boy travels y/4. Then t1 = y/4(z+x)
Let t2 be the time if boy travels 3y/4. Then t2 = 3y/4(z-x)
Now, for a moment assume y/4(z+x) > 3y/4(z-x)
=> 1/(z+x) > 3/(z-x)
=> (z-x)/(z+x) > 3
Now, since z & x both are positive, it can't be true. So, the assumption we had taken is wrong i.e. t2>t1. Hence the boy should travel in original direction he was travelling and cover 3y/4 distance in order to gain more time.
Any clap for me?? Plz respond
