A train is travelling at a speed of 90 km/h brakes are applied so as to produce a uniform acceleration of -0.5 m s-2. Find how far the train will go before it is brought to rest .
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Expert's answer
2011-06-09T14:33:44-0400
First find the time after which the train stops. v=v0-a*t=0, where v0=90 km/h=90/3,6 m/s = 25m/s - initial velocity v=0 the velocity when the train stops t - time
Hence t=v0/a=50 s in that formula we take the module of a
The distance travelled s=v0*t-a*sqr(t)/2 after substituting the value of t to the last formula we'll get the value of distance s=625 m
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