A train starts from rest and accelerates uniformly until it has traveled 2.1 km and acquired a forward velocity of The train then moves at a constant velocity of for 400 s. The train then slows down uniformly at until it is brought to a halt. The distance traveled by the train while slowing down is closest to A train starts from rest and accelerates uniformly until it has traveled 2.1 km and acquired a forward velocity of The train then moves at a constant velocity of for 400 s. The train then slows down uniformly at until it is brought to a halt. The distance traveled by the train while slowing down is closest to 3.8 km. 4.2 km. 3.6 km. 4.4 km. 4.0 km.

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boffeemadrid boffeemadrid · Answer 1 · 2019-10-15T06:35:29+02:00

Answer:

4.4 km

Explanation:

t = Time taken

u = Initial velocity = 24 m/s (Assumed)

v = Final velocity

s = Displacement

a = Acceleration = -0.065 m/s² (Assumed)

Distance = Speed × Time

[tex]\text{Distance}=24\times 400=9600\ m[/tex]

The train travels for 9600 m.

[tex]v=u+at\\\Rightarrow 0=24-0.065t\\\Rightarrow t=\frac{-24}{-0.065}=369.23\ s[/tex]

[tex]s=ut+\frac{1}{2}at^2\\\Rightarrow s=24\times 369.23+\frac{1}{2}\times -0.065\times 369.23^2\\\Rightarrow s=4430.76\ m[/tex]

The Distance the train traveled when it slowed down is 4.4 km