Answer:
43.4 s
Explanation:
First of all, we can find the acceleration of the train by using the equation:
[tex]v^2 -u^2 = 2ad[/tex]
where
v = 39.9 m/s is the final speed
u = 18.2 m/s is the initial speed
a is the acceleration
d = 1250 m is the distance covered
Solving for a,
[tex]a=\frac{v^2-u^2}{2d}=\frac{(39.9 m/s)^2-(18.2 m/s)^2}{2(1250 m)}=0.50 m/s^2[/tex]
And now we can fidn the time taken, by using the formula:
[tex]a=\frac{v-u}{t}\\t=\frac{v-u}{a}=\frac{39.9 m/s-18.2 m/s}{0.50 m/s^2}=43.4 s[/tex]
