The handbrake is used to stop a stationary car rolling downhill. The transmission can also stop a car from moving when parked.
Stationary is an adjective: 'I parked my car on a steep hill and made sure that it was stationary before I walked away.'
Friction of the tires on the road surface ( I think so)
To avoid the car from rolling forward.
It is normal for the car to move a little before the parking mechanism engauges.
Maybe you are parked on a hill. This makes it harder sometimes to get out of park when you are parked on a hill.
That was a very steep hill!
A hill has steep sides because of how the hill formed it formed with steep sides. I don't agree. Hills have steep sides because of the Earth's plates. When the plates push against each other, they sometimes push up, creating a hill or a mountain. Whether the hill has steep sides or not depends on the factors such as weathering and erosion, and on quite simply how it forms.
Yes, More potential energy yES
It could slip out of park, but most likely would "park lock." This would mean the parking pawl would jam inside other parts in the transmission, making it tough to get your car out of park. Sometimes pushing the car is the only way. Use the parking brake on a hill.
The bright green hill was very,very steep therefore i didn't run down the hill.
You can save gas driving a steep hill by driving the car at a lower RPM.
If you are parked on a steep hill or the front wheels are parked hard up against a curb it may cause that to happen. It may take some force to get it out of park. If that fails to work, check for a blown fuse.