The acceleration is constant. The velocity changes. At the top of an arc, the velocity is zero, but it begins to fall due to the constant acceleration. 9.81 meters per second towards Earth. Basic physics, here.
Sorry, just being really anal about technicalities here.
Well, at the top of the flight, the acceleration is zero. If there is a way you can detect this with the accelerometer on the phone, that would be the moment to take the picture. I don't know how the accelerometers work on the n900, but that's the main idea.
I need a facepalm on the double...
because your idea was already addressed at least twice in this thread:
Well.. you should all try accDisplay since physics are not helping. The reason why the phone's accel. readings are all zero (and not 1g) is because all the phone parts (including the accelerometer's internals) are (de)accelerating equally. Accelerometers measure acceleration differences relating to "free-fall". Wikipedia might help
For example, the ISS "feels like" zero G (and indeed a accelerometer there will read 0) only because it's indefinitely falling towards earth: orbiting.
The acceleration is constant. The velocity changes. At the top of an arc, the velocity is zero, but it begins to fall due to the constant acceleration. 9.81 meters per second towards Earth. Basic physics, here.
Sorry, just being really anal about technicalities here.
If the velocity changes the acceleration cannot be constant. Thats the very definition of acceleration, acceleration means how the speed changes in time.
Youre right, at the top of thearc velocity is zero, but the phone has accelerometers, not velocimeters. So at the top of the ark, i think the accelerators in the phone detect 0 acceleration. I don't know exactly how they are build and what exactly are detecting but i think my reasoning is correct.
If the velocity changes the acceleration cannot be constant. Thats the very definition of acceleration, acceleration means how the speed changes in time.
Youre right, at the top of thearc velocity is zero, but the phone has accelerometers, not velocimeters. So at the top of the ark, i think the accelerators in the phone detect 0 acceleration. I don't know exactly how they are build and what exactly are detecting but i think my reasoning is correct.
There is wrong and there is VERY WRONG;
Your reasoning is VERY WRONG.
Dou you have a n900? can you please use the accdisplay app? (on extras-testing now).
With all this accelerometer action there seems to be a missing feature PORTRAIT MODE
Really, a PORTRAIT MODE on this app won't help much since it will be switching portrait-landscape-portrait-landscape during "take-off" and specially during landing and thus eating lots of CPU and then probably messing up with the time readings (start & end).
App is in going to extras-testing this afternoon.. please give it some thumbs up!
I installed the program, started it and threw my n900 in the air couple of times (1-2 meters). Nothing happened. All numbers still 0.0 after the throw. Rebooted N900 and tested again. Still nothing. Installed AccDisplay to make sure that accelerometer works. Accelerometer seems to work.
