Science & Mathematics - 21 July 2007

1) Answer all that are correct-
You run and jump on a swing. During which of the following motions is the total momentum of you and the swing conserved?
running at the swing (and accelerating)
jumping on the swing (the "collision" between you and the swing)
swinging up on the swing
swinging down on the swing
2)Answer all that are correct-
You run and jump on a swing. During which of the following motions is the total mechanical energy of you, the swing, and the Earth conserved? (Assume that the swing is well made so friction can be ignored.)
running at the swing (and accelerating)
jumping on the swing (the "collision")
swinging up on the swing
swinging down on the swing
3) Momentum conservation occurs whenever
the net external force on the objects is zero
the work on the objects is zero
two objects are stuck together
two objects are pulled apart

2007-07-21 20:53:27 · 3 answers · asked by Anonymous in Physics

1. suppose a free falling object is equipped w/ an odometer, would the readings of distance fallen for each sec indicate equal or different falling distances for successive seconds?

2. for a free falling object dropped from rest, what's the acceleration at the end of the 5th sec of fall? 10th sec?

3. by how much does the speed of a ball decrease each second while ascending when it's thrown up?
w/out air resistance, how much does it increase each sec while descending? how much time is required for rising compared to falling?

4. which ball will have a greater speed when it strikes the ground below? one thrown up or down with the same initial speed. [air resistance is negligible]

5. answer question 4 where air resistance is not negligible?

2007-07-21 20:40:57 · 1 answers · asked by sheran g 1 in Physics

2007-07-21 20:36:53 · 11 answers · asked by leroy S 1 in Mathematics

your answer is highly appreciated..
this would be a lot of help for me to help the environment...

2007-07-21 20:27:28 · 3 answers · asked by prapra 1 in Earth Sciences & Geology

2007-07-21 20:16:27 · 3 answers · asked by iLOVEmanila 2 in Physics

please state resources

2007-07-21 20:11:13 · 2 answers · asked by Pat 2 in Geography

please explain

2007-07-21 20:07:49 · 8 answers · asked by Sheridan G 2 in Physics

2007-07-21 20:02:37 · 4 answers · asked by Sheridan G 2 in Physics

2007-07-21 19:59:44 · 3 answers · asked by kalika 1 in Astronomy & Space

what is the impact speed when a car moving at 100 km/h bumps into the rear of another car traveling in the same direction at 98 km/h

2007-07-21 19:55:00 · 2 answers · asked by daisy 2 in Physics

2007-07-21 19:49:06 · 14 answers · asked by Vanity 1 in Mathematics

2007-07-21 19:48:16 · 4 answers · asked by Vanity 1 in Mathematics

2007-07-21 19:46:02 · 6 answers · asked by Anonymous in Biology

If anyone know the answer, i'll appreciate it. I think it's got something to do with hydrogen bonding, but then I might be wrong.....

2007-07-21 19:37:20 · 8 answers · asked by Anonymous in Chemistry

What happens when oil is extracted from deep extraction?

2007-07-21 19:32:23 · 2 answers · asked by ambrosecitadel 1 in Earth Sciences & Geology

2007-07-21 19:31:54 · 9 answers · asked by Anonymous in Weather

they appear in my flour, cereral, rice. small dark colored bug.

2007-07-21 19:30:11 · 3 answers · asked by Lynn 4 in Zoology

My understanding is that this is going to happen in 2008

2007-07-21 19:22:42 · 4 answers · asked by Anonymous in Earth Sciences & Geology

If I were to take this spaceship, and fly it very close to the moon, and then set my weapon arsenal off all at once, could I blow this hanging hunk of cheese out of the sky for good????? Or would I need more than 100 nuclear weapons???

2007-07-21 19:17:56 · 11 answers · asked by Michael K. 1 in Astronomy & Space

My NNF would be corn starch and water, shot with a small caliber rifle round, maybe a .22. Would it stop the bullet?

I think Im going to try it but I want to hear from the people.

2007-07-21 19:16:18 · 5 answers · asked by Mike D 2 in Physics

when consumers apply for credit, their credit is rated using FICO (Fair, Issac, and company) scores. Credit ratings are given below for a sample of applicants for car loans. Use sample data to construct a 99% confidence interval for the standard deviation of FICO scores for all applicants for credit.

661 595 548 730 791 678 672 491 492 583 762 624 769 729 734 706


*****please kindly show how u got the standard deviation thanks:-)

2007-07-21 19:16:08 · 3 answers · asked by delkkis 1 in Mathematics

Here's a challenge problem I thought up relating to interstellar travel at relativistic speeds.

Your spaceship is in Earth orbit. You want to journey to Proxima Centauri, which is 4.22 light-years away, then return to Earth. Your ship is capable of traveling at any speed between 0 and c, the speed of light. If you make the journey at close to the speed of light, time dilation will cause many years to pass back on Earth. However, if you travel extremely slowly, the trip will take a long time.

What fraction of the speed of light do you travel to minimize the amount of time that passes on Earth during your round trip to Proxima Centauri?

10 points to the first correct answer!

2007-07-21 19:03:27 · 4 answers · asked by lithiumdeuteride 7 in Physics

...then is it possible that they could turn blind?
please answer with scientific information if you can, i gotta learn a lot about this

2007-07-21 18:52:15 · 2 answers · asked by orassen 1 in Physics

i need a hint/ help on this geology question for 4,5,and 6.it sounds stupid.i dont know waht they are trying to say.ive tried every thing..still dont get it -_-;;; this will mean a lot to me.if i freakn understand it~ thanks in advance http://www.sciencecourseware.org/VirtualRiver/Files/page08b.html

2007-07-21 18:46:50 · 2 answers · asked by linda y 1 in Earth Sciences & Geology

hi everyone

i just did a course on space law and im studying for my exam, so if u have any questions regarding the politics please post some up, either here or outside it, so that firstly i can quiz myself and maybe i can help answer a few questions

although i see that most here are interested in the sciences, we're looking more towards satellites, star wars, space tourism etc

2007-07-21 18:39:28 · 4 answers · asked by ghostdude! 4 in Astronomy & Space

1. can an automobile with a velocity toward north simultaneously accelerate toward the south?
2. can an object reverse its direction of travel while maintaining an constant acceleration? if so site examples if not explain why?
3. starting from rest one car accelerates to a speed of 50km./hr. and another car accelerates to a speed of 60 km./hr. can you say which car underwent greater acceleration? why?
4. Cite an example of something that undergoes acceleration while moving at constant speed. Can you also give an example of something that accelerates while traveling at constant velocity? explain
5. cite en example of something with a constant speed that has a varying velocity? cite also an example that has varying speed that has constant velocity. explain
6.can an object be moving with zero acceleration? cite example Can an object accelerate with a speed of zero?if so give example
7can you cite an example wherein the acceleration of the object is opposite in direction of its velocity?

2007-07-21 18:37:33 · 2 answers · asked by Anonymous in Physics

2007-07-21 18:37:22 · 4 answers · asked by samuraihero1992 2 in Physics

I got this question asking for the flux of a curl F = (-2x^2)yi + 4xy^2j + z^2k, and is contained by the shell 2 - (x^2 + y^2) = z
above the xy plane.

I went through it but my answer came out weird. Any suggestions?

2007-07-21 18:33:46 · 1 answers · asked by toucansurfer 1 in Mathematics

2007-07-21 18:32:04 · 8 answers · asked by Blake S 1 in Medicine

I love the mountains and am thinking of re-locating from flat Dallas to a city that is high up in mountains with pine trees. I dont mean a city surrounded by mountains, but one on the hills, and not a small town, but a medium to big size city.

Which would it be in the lower 48 states? I can't wait to dump these flat as ironboard surroundings.

2007-07-21 18:23:50 · 8 answers · asked by Anonymous in Geography