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A 250 m train travels through a 2km tunnel at 27 km/hr. How long is it from
the time the front of the train enters the tunnel, to when it completely leaves
it?

 Apr 11, 2020
 #1
avatar+9479 
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A 250 m train travels through a 2km tunnel at 27 km/hr. How long is it from
the time the front of the train enters the tunnel, to when it completely leaves
it?

 

Hello Guest!

 

\(v=\frac{s}{t}\\ t=\frac{s}{v}\\ s=2km+250m\\ s=2250m\)

 

\(v=\frac{27km}{h}\cdot \frac{h}{3600sec}\cdot \frac{1000m}{km}\\ v=7.5\frac{m}{sec}\)

 

\(t=\frac{s}{v}=\frac{2250m\cdot sec}{7.5m}\)

\(t=300sec\cdot\frac{1min}{60sec}\)

 

\(t=5min\)

 

The train is in the tunnel for 5 minutes.

laugh  !

 Apr 11, 2020
edited by asinus  Apr 11, 2020

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