84. Consider the following actions:

1. Detection of car crashes/collisions which results in the deployment of airbags almost instantaneously. hal Exam

2. Detection of accidental free fall of a laptop towards the ground which results in the immediate turning off of the hard drive

3. Detection of the tilt of the smartphone which results in the rotation of the display between portrait and landscape mode.
In how many of the above actions is the function of the accelerometer required?