Answer
$ V = 7.7\times 10^3 m/s $
Work Step by Step
If all this energy is used to accelerate a 1000-kg car from rest, then:
$$\Delta U = 0.5 m V^2 $$
$$ V = \sqrt \frac{2\Delta U}{m} $$
We plug in the known values to obtain:
$ V = 7.7\times 10^3 m/s $
