Yes true to gravity,9.8m/s iirc however,heavy objects do accelerate faster to that speed................
OK, not to be too much of a smartypants, but this is a technical discussion forum, and it's almost on topic for this SS light, relating to it's non-illuminating performance due to higher mass, sooo...
In a vacuum, there is never any difference in speed or acceleration of all objects falling. I had the opportunity to see this for myself in college physics. The prof. had about an eight foot tall clear plastic tube with an electromagnet at the top. Inside, he trapped a feather against the magnet with a steel ball. Then he sealed the tube and pumped out all of the air. On turning off the power to the magnet, the ball fell to the bottom of the tube. And you guessed it, the feather fell right with it and they landed together just as they started.
So as I eluded to above, differences will occur when air resistance over the surface area becomes significant. Skydivers are *very* thankful that this is so. But given the difference in mass of the two lights, which is only a portion of the whole key ring, which doesn't have a lot of area to generate resisting force in the air, I say the keys with the SS light reach the ground within 1% of the same time/speed as the ones with the aluminum one, or no measurable difference.
Yeah, I am an engineer. BTW, I taught two semesters of that same mechanical physics course for the self-study version of the course. They didn't let me play with the vacuum tube though. :mecry: