It's About Time C

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Re: It's About TIme

Post by UTF-8 U+6211 U+662F » February 21st, 2015, 8:59 am

finagle29 wrote:I think it's about time someone answered your question
Greenwich Mean Time, Universal Coordinated Time, Atomic International Time, Before Common Era, Common Era
Correct, although I thought UTC meant Coordinated Universal Time and TAI International Atomic Time.
:) Word Order :)

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Re: It's About TIme

Post by finagle29 » February 22nd, 2015, 8:45 am

oh word order, how thine importance doth matter so. I should probably double check my word orders because some event supervisors are likely to be very unforgiving when it comes to breaking ties.

anyway
For what order chemical reaction does the half-life depend solely on rate constant?
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Re: It's About TIme

Post by Ionizer » February 22nd, 2015, 9:11 am

finagle29 wrote:oh word order, how thine importance doth matter so. I should probably double check my word orders because some event supervisors are likely to be very unforgiving when it comes to breaking ties.

anyway
For what order chemical reaction does the half-life depend solely on rate constant?
First Order
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Re: It's About TIme

Post by finagle29 » February 22nd, 2015, 9:46 am

Correct!
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Re: It's About TIme

Post by Ionizer » February 22nd, 2015, 10:14 am

ok
Superman is flying at a constant speed and constant height around the Earth. Superman has a mass of 112.35 kg, and he is flying 1235.7 m above the Earth. He experiences a centripetal force of 204065.010845 N. How many seconds does it take Superman to make one rotation around the Earth? Use proper significant figures
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Re: It's About TIme

Post by boomvroomshroom » February 25th, 2015, 9:34 am

~372s (using 6.38E6 as Earth's radius)
F=mv^2/r, d=2(pi)r=vt

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Re: It's About TIme

Post by JonB » February 25th, 2015, 9:48 am

Ionizer wrote:ok
Superman is flying at a constant speed and constant height around the Earth. Superman has a mass of 112.35 kg, and he is flying 1235.7 m above the Earth. He experiences a centripetal force of 204065.010845 N. How many seconds does it take Superman to make one rotation around the Earth? Use proper significant figures
.
From team member:
since F_c = m v^2 / r, and all the terms but v are given, the solution is v = (F_c r / m)^.5. then since distance = speed*time, 2 pi r = vt
using r_e = 6378100, and adding his flying height to the earth's radius to come up with an r of 6379335.7, the answer for v is 1.0764*10^5.
then, since distance = speed*time, 2 pi r = vt and t = 2 pi r / v, so t = 372.37s
the poster above shouldn't forget sigfigs

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Re: It's About TIme

Post by Ionizer » February 25th, 2015, 11:29 am

JonB wrote:
Ionizer wrote:ok
Superman is flying at a constant speed and constant height around the Earth. Superman has a mass of 112.35 kg, and he is flying 1235.7 m above the Earth. He experiences a centripetal force of 204065.010845 N. How many seconds does it take Superman to make one rotation around the Earth? Use proper significant figures
.
From team member:
since F_c = m v^2 / r, and all the terms but v are given, the solution is v = (F_c r / m)^.5. then since distance = speed*time, 2 pi r = vt
using r_e = 6378100, and adding his flying height to the earth's radius to come up with an r of 6379335.7, the answer for v is 1.0764*10^5.
then, since distance = speed*time, 2 pi r = vt and t = 2 pi r / v, so t = 372.37s
the poster above shouldn't forget sigfigs
Correct. If you used the mean radius of the Earth(6371000 m) instead of the equatorial radius then it takes
372.16
seconds, but I didn't specify which to use.
Last edited by Ionizer on February 25th, 2015, 11:54 am, edited 3 times in total.
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Re: It's About TIme

Post by Ionizer » February 25th, 2015, 11:45 am

boomvroomshroom wrote:
~372s (using 6.38E6 as Earth's radius)
F=mv^2/r, d=2(pi)r=vt
also correct(ignoring sig figs)
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Re: It's About TIme

Post by finagle29 » February 25th, 2015, 2:51 pm

Hey Ionizer, its considered bad forum etiquette to double post. No hard feelings, but in the future keep in mind that you can edit your post.
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