Q1 A train is travilling at speed of 90km h-1. brakes are applied so as to produce a uniform acceraleration -0.5 m/ s-2 . find how far the train will go before it is brought to rest?
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Q1 A train is travilling at speed of 90km h-1. brakes are applied so as to produce a uniform acceraleration -0.5 m/ s-2 . find how far the train will go before it is brought to rest?
PLZZZ ANSWER MY QUESTION
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Explanation:
speed = 90km/h = 5×90/18 = 25m/s
acc = - 0.5m/s^2 , v = 0
using second equation of motion,
v^2 - u^2 = 2as
a is acc , s is distance, v is final velocity u is initial velocity
0^2 -( 25^2 ) = 2 (- 0.5)(s)
-625 = -s
s = 625m
using first equation of motion,
v = u + at
0 = 25 + (-0.5)(t)
-25/-0.5 = t
t = 50 sec