Answer
$t=7.72s$
Not realistic
Work Step by Step
As the problem is in a level road the work needed to accelerate the car only depends on the kinetic energy:
$W_{k}=\frac{1}{2}m\Delta v^2=\frac{1}{2}*1500kg*((100\frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s})^2-(0\frac{m}{s})^2)$
$W_{k}=578.70kJ$
And the time neede is:
$t=\frac{W_{k}}{P}=\frac{578.70kJ}{75kW}=7.72s$
This answer is not realistic because the friction and air resistance were not take in count.
