StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>The most important concept to understand before reading my post is that <strong>acceleration relative to the ground</strong> (<em>not</em> accelerometer reading) due to gravity will always be 1.0g. However, this acceleration can be diminished/enhanced by external factors such as air resistance, stopping force, applied force, etc.</p> <p>It is important to recognize the difference between actual acceleration and the accelerometer reading before noticing the variation between my answer and the others. I have answered your question in terms of acceleration because your graph does not seem to reflect raw accelerometer readings, but rather acceleration relative to the ground. To clarify:</p> <ul> <li>Accelerometer value = abs(acceleration WRT ground - 1g)</li> </ul> <p>Therefore:</p> <ul> <li>When acceleration is 0g (object is at rest), the accelerometer reads 1g.</li> <li>When acceleration is 1g (object is in free fall), the accelerometer reads 0g.</li> </ul> <p>Here is a probable situation for each acceleration WRT ground that you posted:</p> <p>1.5g: When dropping the iPhone, you probably accidentally applied a small force of ~0.5g, causing an acceleration of 1.5g (1.0g due to gravity + 0.5g applied).</p> <p>1.0g: Once it is in actual free fall, it reads ~1.0g (acceleration due to gravity). This is the acceleration it should hypothetically be reading the entire time it is in free fall, neglecting air resistance.</p> <p>2.5g: When it hits the pillow, it has an upwards acceleration of ~2.5g because it is stopping after having gained speed from gravity.</p> <p>0.0g: After it has stopped, it has 0.0g of acceleration because it isn't accelerating. Acceleration due to gravity has been neutralized by the normal forced exerted by pillow.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload