Calculate the net work done to accelerate a 1500 kg car from 10m/s to 20m\s

There are two ways to do this one.
In due consideration of 5 points, I have decided
to do it the easy way.

Kinetic energy = (1/2) (mass) (speed²)

The car's KE at the slower speed = (1/2 mass) x (10²)

                                                     =     75,000 joules .

The car's KE at the faster speed =  (1/2 mass) x (20²)

                                                     =    300,000 joules .

The difference in kinetic energy between
the slower and faster speeds =

                                       (300,000  -  75,000) = 225,000 joules.

THAT's the work that had to be done in order to accelerate
the car to double the original speed.