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.
