18. A car has mass 1500 kg. It is traveling at 25 m/s before going downhill and dropping a vertical distance of 15 m to ground level h = 0 m. Afterwards, it encounters a shock absorber with spring constant 150 kN/m and is brought to a halt. Assuming there is no friction, what is the total energy of the car at the bottom of the hill? O 694 kJ O 225 kJ O 250 kJ O 469 kJ O OJ