Just one question,if only handbrake or only gear is applied when the car is in aslope,is there any danger?Because the handbrakes were applied but the gear was in neutral position when this incident happened.
Dear Shrijit,
Never slot it in Neutral.
Make sure the gear is either in 1st or reverse.
If you have parked the car on a slope with the car facing uphill, slot it in 1st with handbrake engaged. If the car is facing downhill, slot it in reverse with the handbrake.
I hope you get the idea.
On a normal plane, engage it in 1st with handbrake.
This helps in locking the wheels. Use 1st or Reverse to lock the wheels opposite to the direction to which it is likely to roll by itself.
In Neutral and only handbrake, the pressure is entirely on the brakes to hold your car on a slope. But engaging the gears will lock the wheels and this assists the handbrake making it very safe for the car to be parked on the slope. Using a rock or a brick at the tires makes it even more safer.
If only gear is engaged without handbrake, the pressure falls on the drivetrain, which will slowly cause wear out of the parts. Similarly, if handbrake alone is used, those parts will wear out sooner.
Best is both always.