It's About Time C
- Bogoradwee
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Re: It's About Time C
those sound really easy.... the last one i'm pretty sure i have in my binder near the front. the other stuff i could do even in my head if i REALLY had to (the seconds in a week wouldn't be very fun)
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- harryk
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Re: It's About Time C
have you done this event yet!?!?Bogoradwee wrote:those sound really easy.... the last one i'm pretty sure i have in my binder near the front. the other stuff i could do even in my head if i REALLY had to (the seconds in a week wouldn't be very fun)
they may sound easy but they are much more difficult
for ex.-
How many time zones are used in the U.S.? (one of the easier ones, don't forget about territoreis)
What is a modified Julian date?
What timezone do they use in the international space station?
and many other harder questions I cant remember right now
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Re: It's About Time C
Has anyone considered making a pendulum that moves in the path of a cycloid? My calculus book says it is a good idea.
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Re: It's About Time C
For people that have been using rigid rod pendulums, what were your masses of the the pendulum and rod? I was trying out a rigid rod and it doesn't seem to last more that a 100 seconds.
My rod is 20 g while the mass I'm using is 250 g. Is weight of the rod the issue or the contact b/w the rod and axle? I'm using a single ball bearing (3/8 in inner diameter, 5/8 in outer diameter) to put them together fyi.
Any help would be appreciated.
My rod is 20 g while the mass I'm using is 250 g. Is weight of the rod the issue or the contact b/w the rod and axle? I'm using a single ball bearing (3/8 in inner diameter, 5/8 in outer diameter) to put them together fyi.
Any help would be appreciated.
- Bogoradwee
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Re: It's About Time C
i've never made a pendulum, but if you have a heavier mass, wouldn't that more force, meaning more energy behind the swing, allowing it to go longer? That just seems to make sense to me, but i can't remember the physics of a pendulum off hand right now, which probably isn't good considering regionals is on saturday
Science Olympiad: Guessing and BSing our way to victory!
Btw, if you see me in IRC chat, I'm Exothermic
2009: I don't remember/ not very noteworthy.
2010: See above.
2011: Regionals- 3rd WIDI, 3rd Optics, 3rd Fossils, 3rd overall States- 4th WIDI
Btw, if you see me in IRC chat, I'm Exothermic
2009: I don't remember/ not very noteworthy.
2010: See above.
2011: Regionals- 3rd WIDI, 3rd Optics, 3rd Fossils, 3rd overall States- 4th WIDI
- harryk
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Re: It's About Time C
adding more weight will not help the time very muchBogoradwee wrote:i've never made a pendulum, but if you have a heavier mass, wouldn't that more force, meaning more energy behind the swing, allowing it to go longer? That just seems to make sense to me, but i can't remember the physics of a pendulum off hand right now, which probably isn't good considering regionals is on saturday
it happens because of other forces such as friction and drag and especially the rigidness of the stand, if it sways with the swing your pendulum will not last long
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- walkingstyx
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Re: It's About Time C
The contact between the rod and axle is more likely to be the issue. The weight of the rod should not be all that significant, though it could be an issue considering how similar the two are in your pendulum.texan92 wrote:For people that have been using rigid rod pendulums, what were your masses of the the pendulum and rod? I was trying out a rigid rod and it doesn't seem to last more that a 100 seconds.
My rod is 20 g while the mass I'm using is 250 g. Is weight of the rod the issue or the contact b/w the rod and axle? I'm using a single ball bearing (3/8 in inner diameter, 5/8 in outer diameter) to put them together fyi.
As I recall, Primate was having similar problems with his rigid pendulum, I think the issue turned out to be the bearing he was using, but you could ask him.
We use an extremely heavy weight at the bottom of our pendulum, several kilograms. Adding weight to the bottom would probably help, but the best way is just to try and see.
Also, the cycloid idea has been on these forums pretty much as long as Time has been around, and nobody has ever reported making one. I think it's too much work for too little return.
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Nationals 2009- Picture This: 4, It's About Time: 8, Astronomy: 9
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Re: It's About Time C
Just click on "Search" in the header menu of any page on these forums and enter "cycloid" in the "Search for Keywords" box. Scroll to the bottom of the page and click the "Search" button. Here's just one of the results returned.
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Re: It's About Time C
Use a bigger mass and look for friction. Ours swings for 25 minutes or more.texan92 wrote:For people that have been using rigid rod pendulums, what were your masses of the the pendulum and rod? I was trying out a rigid rod and it doesn't seem to last more that a 100 seconds.
My rod is 20 g while the mass I'm using is 250 g. Is weight of the rod the issue or the contact b/w the rod and axle? I'm using a single ball bearing (3/8 in inner diameter, 5/8 in outer diameter) to put them together fyi.
Any help would be appreciated.
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Re: It's About Time C
WOW, what is the size of your mass?Flavorflav wrote:Use a bigger mass and look for friction. Ours swings for 25 minutes or more.texan92 wrote:For people that have been using rigid rod pendulums, what were your masses of the the pendulum and rod? I was trying out a rigid rod and it doesn't seem to last more that a 100 seconds.
My rod is 20 g while the mass I'm using is 250 g. Is weight of the rod the issue or the contact b/w the rod and axle? I'm using a single ball bearing (3/8 in inner diameter, 5/8 in outer diameter) to put them together fyi.
Any help would be appreciated.
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