Final answer:
When parking uphill with a curb, turn your wheels away from the curb. When parking uphill without a curb or when parking downhill with or without a curb, turn your wheels to the right. This ensures your car will not roll into traffic if it starts to move.
Step-by-step explanation:
How to Park on Hills
When parking uphill or downhill, the way you position your wheels is crucial for safety. If you're parking uphill without a curb, turn your wheels to the right, so that if your car starts to roll, it will go off the road rather than into traffic. Conversely, when parking uphill with a curb, turn your wheels away from the curb and let your vehicle roll back a bit so the front right tire rests against the curb, acting as a block.
For downhill parking, whether there is a curb or not, you should turn your wheels to the right. This ensures that if the car rolls, it will roll away from traffic or into the curb, helping to stop the vehicle.
By correctly positioning your wheels, you're using the mechanical energy conservation concept as a practical application. At rest, cars have potential energy based on their elevation. When a car rolls downhill, potential energy is converted into kinetic energy - both rotational and translational - as the car moves. Proper wheel alignment when parked ensures this energy does not cause your vehicle to roll into traffic.