The Definition of Work is given by:
Entering the unknowns, we have:

If you notice any mistake in my english, please let me know, because i am not native.
Answer:
2.9
Explanation:
es 2 minutos con 9 segundos seria algo así (1450)÷(500)
The velocity of the car at the bottom of the hill=19.8 m/s
mass= 100 kg
height= h=20 m
Velocity at the bottom=V
Using the law of conservation of energy
potential energy at top = kinetic energy at the bottom
m g h= 1/2 m v²
g h= 1/2 v²
9.8 (20)=1/2 V²
V=19.8 m/s
Thus the velocity of car at the bottom of hill=19.8 m/s