Question

A train traveling at 18.2 m/s accelerates to 39.9 m/s over a distance of 1250 m. How long did it take the train to cover this distance?

Answer 1

Answer:

43.4 s

Explanation:

First of all, we can find the acceleration of the train by using the equation:

$v^2 -u^2 = 2ad$

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,

$a=\frac{v^2-u^2}{2d}=\frac{(39.9 m/s)^2-(18.2 m/s)^2}{2(1250 m)}=0.50 m/s^2$

And now we can fidn the time taken, by using the formula:

$a=\frac{v-u}{t}\\t=\frac{v-u}{a}=\frac{39.9 m/s-18.2 m/s}{0.50 m/s^2}=43.4 s$