Science & Mathematics - 8 October 2007

a 81.0 kg person is standing on a scale in an elevator. what is the apparent weight when the elevator is

(a) accelerating upward with an acceleration of 1.80 m/s^2?

(b) moving upward at a constant speed?

(c) accelerating downward with an acceleration of 2.00 m/s^2?

i really am stuck. please help me. i don't know how to do this!!

please, Please, PLEASE help me!!!

thank you!

2007-10-08 10:56:03 · 2 answers · asked by Elizabeth 3 in Physics

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A 0.25kg model rocket accelerates from 15 m/s to 40 m/s in 0.60 s.Calculate the force(s) exerted on the rocket

2007-10-08 10:55:32 · 2 answers · asked by Anonymous in Physics

1 ⤊

Does the engine of a space shuttle produce sound as it orbits Earth?

2007-10-08 10:54:52 · 5 answers · asked by emoicdollface305 1 in Astronomy & Space

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What are some groups that are working towards reducing pollution in the bay?

Please, help!

2007-10-08 10:54:05 · 1 answers · asked by Anonymous in Earth Sciences & Geology

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what is the mass # and atomic # of this isotope notation 24/12 Mg?

24
12Mg

that Mg is supost to be between the 2 numbers not on the bottom or top specifically.

2007-10-08 10:53:33 · 2 answers · asked by Anonymous in Chemistry

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The mixing of water and changes in temperature?

What will the temperature be of 165 mL H2O at 22 C mixed with 85 mL H2O at 82 C? How do you get this?

2007-10-08 10:51:22 · 1 answers · asked by Anonymous in Chemistry

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heyy!!!!!!!!!!!!!!!!!!?

can you please convert 373 kelvin to celsius please!

2007-10-08 10:49:02 · 1 answers · asked by ? 3 in Chemistry

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How many grams of H2 would be in a 3.0 L container of H2?

show work

2007-10-08 10:48:56 · 2 answers · asked by Katrina r 1 in Chemistry

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geometry help?

I know this sounds like a stupid question but I got really sick and missed a ton of class so im being really paranoid about getting everything right. So thanks if you'll help.

Are two different triangles always, sometimes, or never congruent? I have sometimes. Is this right. Once again thanks and sorry for such a stupid question.

2007-10-08 10:48:02 · 4 answers · asked by Anonymous in Mathematics

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How does the chromosome number change throughout the human life cycle.?

2007-10-08 10:47:11 · 2 answers · asked by lil_princess07us 1 in Biology

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Is the Earth slowly moving further away from or closer to the sun over time?

If the Earth is traveling around the more massive sun, what keeps the earth from eventually crashing into the sun? What is the driving force that is resulting in a net migration of the Earth towards or away from the sun over millions of years?

2007-10-08 10:46:16 · 14 answers · asked by DBrain 1 in Astronomy & Space

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Do you know a really fun but will still get me an A science project?

I have to do an 8th grade science project but I have on idea what I'm going to do.
I think the stars and the moon ane the sun are really cool...got any ideas on that.
8th grade please

2007-10-08 10:44:26 · 1 answers · asked by Anonymous in Astronomy & Space

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(x+7) (x+1)?

multiply

2007-10-08 10:43:49 · 5 answers · asked by WILLIAM M 1 in Mathematics

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Why do you suppose CCDs are preferred for producing astronomical images?

Do you think it's because they are so compact in size, that they register more photons than photographic plates do, that telescopes using CCDs have to be focused on the subject for shorter times or for all of these reasons?

Thanks.

2007-10-08 10:43:30 · 1 answers · asked by higherlovetx 5 in Astronomy & Space

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If space itself was created during the Big Bang, what preceded it and what is it expanding into?

2007-10-08 10:42:51 · 6 answers · asked by Anikin 1 in Astronomy & Space

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What kind of camera does NASA use to capture images while in space?

I know what certain vessels carry them, but what are the specifications? Why/How are the images so clear? Does NASA make the camera? etc..

2007-10-08 10:42:41 · 3 answers · asked by T-Rev 1 in Astronomy & Space

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Statistical equation required.?

52 Manchester United games are observed. The league position of Manchester and their opponent are taken before the game.
i.e. If Manchester are 4th placed and Liverpool are 8th then Manchester have +4points. If Manchester are 9th place and Arsenal 2nd then Manchester have -7points.

After 52 games it was observed that:
+19 points [2wins to Manchester, 0 draws, 0 losses]
+17 [3,0,0]
+15 [1,1,0]
+14 [0,1,0]
+11 [2,1,0]
+8 [0,0,1]
+5 [2,0,0]
+4 [2,1,0]
+2 [6,2,0]
+1[1,1,1]
-1 [2,0,2]
-3 [1,3,5]
-5 [0,1,0]
-6 [0,1,4]
-9 [1,0,1]
-12 [0,1,2]

From this data what equation can be used to calculate the probability of a Manchester United win, draw or loss for any given points (league placing) between the two teams?

i.e. From this data what is the probability of Manchester winning if they are 3rd place against 2nd place Chelsea?

Hope this makes sense, sure there is some statistical method that can be applied to this.

Thanks.