Question

Light-rail passenger trains that provide transportation within and between cities speed up and slow down with a nearly constant (and quite modest) acceleration. A train travels through a congested part of town at 5.0 m/s. Once free of this area, it speeds up to 12 m/s in 8.0 s. At the edge of town, the driver again accelerates, with the same acceleration, for another 16 s to reach a higher cruising speed. What is the final speed?

Answer 1

Answer:

26m/s

Explanation:

Assuming that the acceleration is constant, we can start by calculating the train speed when it's free of the congested area:

$a = \frac{\deltav}{\deltat} = \frac{12 - 5}{8} = \frac{7}{8} = 0.875 m/s^2$

Then with the same acceleration we can find out the final speed:

$v = v_0 + at = 12 + 0.875*16 = 26m/s$