Question

Lucifer is in a train traveling initially at 5.48 m/s west when she begins to accelerate west at the rate of 0.892 m/s/s for a time of 6.90 s. What is her velocity at the end of the acceleration?

Answer 1

Recall that

$v_f=v_i+at$

which follows from the definition for average acceleration. So Lucifer has a final velocity of

$5.48\dfrac{\rm m}{\rm s}+\left(0.892\dfrac{\rm m}{\mathrm s^2}\right)(6.90\,\mathrm s)\approx\boxed{11.6\dfrac{\rm m}{\rm s}}$