Question 884587: You are standing 1/3 of the length in on the bridge and can run with a speed of 20 Km/h
Here we can choose two scenarios:
1. You run 1/3 of the bridge's length in the direction of the train and is just fast enough to fling you off the bridge before being hit by the train.
2. You run 2/3 of the bridge's length away from the train, also here just in time to throw you off the bridge before the train hit you.
What is the speed of the train?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! You are standing 1/3 of the length in on the bridge and can run with a speed of 20 Km/h
Here we can choose two scenarios:
1. You run 1/3 of the bridge's length in the direction of the train and is just fast enough to fling you off the bridge before being hit by the train.
2. You run 2/3 of the bridge's length away from the train, also here just in time to throw you off the bridge before the train hit you.
What is the speed of the train?
:
We know from the information given, that you will have run 1/3 of the bridge length when the train enters the bridge.
:
You will be 1/3 away from far end then. (You're running away from the train)
:
The train travels the full length of the bridge while you travel 1/3.
:
therefore the train is running 3 times your speed
3 * 20 = 60 km/h is the train speed
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