What adjustments would you have to make to build a pendulum clock on the moon, or on Mars? What about on Jupiter?
I need the answer soon because… well, it’s secret, but it involves rocket boots, a fish bowl, and a whole bunch of cheese. 
[size=1]While I’m on the Moon, does anybody need anything?
I’m not a clock builder but I thought the point of a pendulum is that each swing takes a constant amount of time (starts out making long swings fast, then gradually becomes short swings slow, but total time for one cycle is constant)?
If that’s the case then I don’t think that you’d have to do anything special to account for different gravity. If the clock was built on earth and then transported to the moon you might need to recalibrate it but from a mechanical standpoint it’d still run fine.
Why do I suspect that “rocket boots, a fish bowl, and a whole bunch of cheese” translates to “the homework is due sooon”?
I don’t know Chronos, he’s been a member an awfuly long time to still be in highschool.
Hey, it was the best seven years of my life.
Could still be in college, though. That question wouldn’t be out of line in our Physics 206 course.
Be nice. If you want to cast aspersions on the guy take it to the Pit.
You know.
Pit the pendulum.
Besides, if it is a school assignment, he may have the Sword of Damacles hanging over him.
Stranger
Nope — not in school, not in college, just planning a trip to the moon and I have to pack soon. 
On Jupiter, the hardest part would be finding somewhere to set it down. Also, building it out of something that can handle a corrosive pressurized hydrogen atmosphere.
OK, I’ll give you the benefit of the doubt. The period of a simple pendulum is given by P = 2pisqrt(l/g), where l is the length, and g is the acceleration due to gravity. If you’re keeping the same innards, and want to run at the correct rate, then you’ll need to keep the pendulum period the same, which means you need to keep the ratio l/g the same. g on the Moon is about 1/6 what it is on the Earth, so you’d need a pendulum of 1/6 the length, as well.
This may or may not be practical: For a pendulum to work well, most of the mass should be in the bob at the end, which should be small compared to the length, which might be harder to construct at 1/6 the scale. It would probably be easier to keep the same (or close to the same) pendulum, and just adjust the gearing inside which transforms the pendulum period to the speed the hands rotate.
Thanks. My grandfather is in the process of building his own wooden clock, and we got to talking at lunch on Thursday about the period of a pendulum.
If you were to divide up the “day” on Mars into 24 bits from noon to noon, just like on Earth, then I presume the interior gearing could be much the same — you’d just have to find a pendulum that had a period of … uh … 1 / 43,200th of that rotational period, right?