Answer
39.2 m
Work Step by Step
Distance travelled before car starts decelerating:
$x=ut=(20.0)(0.530)=10.6\; m$
Distance travelled while decelerating:
$v^{2}=u^{2}+2ax$
$x=\frac{v^{2}-u^{2}}{2a}=\frac{0^{2}-20.0^{2}}{2(-7.00)}\approx28.57\; m$
Stopping distance = 10.6 + 28.57 $\approx$ 39.2 m
