Question

A car accelerates uniformly in a straight line
from rest at the rate of 2.8 m/s^2.

What is the speed of the car after it has
traveled 69 m?
Answer in units of m/s.

Answer 1

Recall that

${v_f}^2={v_i}^2=2a\Delta x$

The car starts from rest, so $v_i=0$, and we get

${v_f}^2=2\left(2.8\dfrac{\rm m}{\mathrm s^2}\right)(69\,\mathrm m)\implies v_f\approx19.66\dfrac{\rm m}{\rm s}$