In a frontal crash test, a 2000 kg car hits a rigid wall at 45 km/h. The deceleration should be limited to 60 g by the crushing of the front end of the car. Find:
1. The crushing force applied by the wall to the front end of the car.
2. The distance traveled by the center of mass (crushing distance) during the crash in order to dissipate all the kinetic energy.
3. How long will the impact last?