Consider the following actions : 1. Detection of car crash/collision which results in the deployment of airbags almost instantaneously 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 display between portrait and landscape mode In how many of the above actions is the function of accelerometer required?

States that vehicles are fitted with instruments (speedometer, odometer) that measure motion-related quantities.

A student could infer that since vehicles already carry motion sensors, other sensors (e.g., accelerometers) could also be installed to measure rapid changes in motion associated with a crash.

Asks whether an object applying force must be in contact, teaching that forces change motion — the underlying concept of acceleration.

Using the basic physics link between force and change in motion, a student could reason that measuring sudden changes in motion (acceleration) can indicate a collision.

Discusses whether a force can change speed or direction, reinforcing that acceleration describes changes in motion.

A student can combine this with knowledge that abrupt large accelerations/decelerations are signatures of crashes and thus detectable by sensors.

Describes an anemometer that converts rotational motion into a measured speed via counting rotations — an example of a sensor converting physical motion into an electrical/counted signal.

By analogy, a student could reason that devices exist which convert mechanical motion (rapid deceleration) into electronic signals that could trigger systems like airbags.

Defines 'debris fall' and 'free fall' as rapid/near-free-fall motions, giving a clear notion of the kind of rapid motion that might be detected.

A student could note that an accelerometer detects rapid changes in acceleration and therefore could be used to recognize such near-free-fall motion in a laptop.

Further describes 'rock fall' and 'free falling' as distinct, rapid motions from steep slopes—another example of sudden acceleration events.

Combine this pattern of sudden acceleration with knowledge that electronic sensors can detect acceleration to hypothesize a laptop sensor detecting accidental falls.

Explains that modern devices measure very short time intervals (milliseconds, microseconds), implying sensors and processors operate fast enough to react quickly to rapid events.

A student could infer that an accelerometer and accompanying electronics could detect a fall and trigger an immediate response (e.g., parking a drive) within the needed short time.

Describes how anemometers convert physical rotation into counts over time to calculate speed—illustrates the general pattern of sensors converting motion into actionable signals.

Use this sensor-to-signal pattern to reason that an accelerometer could convert acceleration during a fall into a signal that commands drive protection.

Mentions laptops as devices containing various components, indicating the context where sensors and protective mechanisms might be integrated.

A student could combine this with knowledge that laptops include multiple internal sensors/components to plausibly situate an accelerometer and drive-parking mechanism inside a laptop.

Mentions smartphones operate by processing signals very quickly (microseconds), implying they have built-in sensors and real-time signal processing capability.

A student could combine this with the basic fact that detecting tilt requires fast sensor reading and processing to conclude smartphones are capable of running such detection algorithms.

States that smartphones can read QR codes with devices, showing smartphones integrate specialized sensing (camera + decoding) and software to interpret external input.

A student might extend this to reason that smartphones commonly include multiple sensors and software for interpreting inputs like orientation.

Explains the concept of rotation and an axis/tilt (Earth's rotation and tilted axis), providing a clear example of 'tilt' and rotational reference frames.

A student could map the general idea of detecting tilt (angle relative to gravity or an axis) from planetary tilt to how a device might detect its own tilt.

Describes how tilt of Earth's axis produces observable changes (seasons), giving another example of tilt producing measurable effects.

A student could use this pattern — tilt causes predictable changes — to infer that a sensor measuring tilt could trigger a predictable change like rotating a display.

Notes that a pinhole camera gives an upside-down image and mirrors cause lateral inversion, highlighting that image orientation can vary and sometimes needs correction.

A student could reason that correcting or adapting image/display orientation is a common requirement in devices that capture or show images, motivating automated rotation based on device orientation.