Question

A car accelerates uniformly in a straight line

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

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