Science & Mathematics - 27 October 2007

How to determine the value? Show me the workings?

Don't ask me to use a calculator..This question came out in paper 1 where calculator is not allowed.

2007-10-27 14:58:45 · 3 answers · asked by Anonymous in Mathematics

Just curious....

2007-10-27 14:57:55 · 13 answers · asked by Anonymous in Zoology

2007-10-27 14:57:24 · 3 answers · asked by nikeboy9_1 1 in Mathematics

I was wondering if you'd be able to help me with this. As of now, I only have a very, very basic understanding of physics. I took it in middle school and now I am being forced to take it again in high school.

This question relates to an assignment I was given in class that I do not understand. I do not expect you to solve this problem for me, but I would like to know if the formulas that I am using are correct, and if I am indeed going in the right direction, because, quite frankly, I can't understand half of the things my teacher says.

4π^2(L/T^2)= g

This is the equation we are dealing with. We're supposed to find what g is. L and T are variables we found by performing an experiment where we swung a pendulum. There are four separate numbers representing L (four lengths of the pendulum) and four numbers representing T that go along with each of the four Ls.

He told us to make two scatter plots, one with L along the y axis and T along the x axis, and one with L along the y axis and T^2 along the x axis. He then told us to draw lines to make them into graphs. He told me that the graph that went (T^2, L) should be a linear function and that the graph with the points (T, L) should be some kind of curved line. I don't know if this is true though, because he didn't seem to be paying attention when I asked him this...

Any way, to solve it via the analytical method, I plugged in an L and a corresponding T. I got an answer for g that was 9.04m/s^2. That doesn't sound right, but it doesn't sound horribly wrong, either.

To solve it via the graphical method, he told us we needed to find the slope of the line of the linear equation with the points (T^2, L). But thing is, I'm not sure where the slope comes into play when solving this problem. Does it replace the T^2 of 4π^2(L/T^2)= g or does it replace the whole L/T^2? Where does this variable go? I'm not sure exactly...I tried putting it in in the place of L/T^2, leaving me with 4π^2(slope)= g. The answer I got for putting it in was 11.05m/s^2. This is very different from the 9.04m/s^2 I got earlier, but it is the closest number that I was able to find...I adjusted the slope of me line multiple times using multiple methods but this was generally the result.

When doing this experiment, is it reasonable to find this kind of the difference in answers between the analytical and graphical methods? What do you think I am doing wrong?

2007-10-27 14:55:57 · 1 answers · asked by Anonymous in Physics

The one in animals and the one in plants??Also what results wil be obtained if the benedict's test is carried out on starch solution?And what is the reason for the results ?Thank You

2007-10-27 14:55:28 · 1 answers · asked by Anonymous in Biology

Which one would an organism whose cell membranes are dominated by saturated phospholipids with extremely long hydrocarbon chains be found???

2007-10-27 14:54:32 · 2 answers · asked by krysta34_45 1 in Earth Sciences & Geology

2007-10-27 14:54:29 · 6 answers · asked by Deenie 6 in Paranormal Phenomena

it is said that the streams flow in the lakes, lakes flow into the rivers, the rivers flow into the oceans, but yet the oceans never fill or over flow,,,why is this an unanswered question of nature.????

2007-10-27 14:54:18 · 5 answers · asked by geraldwarden 1 in Earth Sciences & Geology

he figure shows two identical blocks tied together with a string which passes over a pulley at the crest of the inclined planes, one of which makes an angle q1 = 29° to the horizontal, the other makes the complementary angle q2 = 61°.
a) If there is no friction anywhere, with what acceleration do the blocks move?

a = m/s2
b) If each block has a mass m = 0.7 kg, what is the tension in the string while they are both moving?

T = N
c) Now suppose the coefficient of sliding friction between the blocks and planes is µ = 0.03. With what acceleration do the blocks move in this case?

af = m/s2

2007-10-27 14:52:55 · 1 answers · asked by GirlYgIRL 1 in Physics

One in animals and one in plants.Also what results wil be obtained if the benedict's test is carried out on starch solution?And what is the reason for the results ty.

2007-10-27 14:52:52 · 1 answers · asked by Anonymous in Biology

2007-10-27 14:52:25 · 1 answers · asked by Foster W 1 in Chemistry

my bio class did an experiment to find the realtionship of PH level with enyme activity.
apparently, the buffer solution was used in the experiment for something about PH.
so my questions are, what is a buffer solution?
what does a buffer solution do?
and does a buffer solution speed up chemical reactions?
tell me everything you know about buffer solutions.
thank you!

2007-10-27 14:51:12 · 3 answers · asked by Anonymous in Chemistry

you are traveling in a space ship at the speed , of light, and you turn on your headlights,, is the light visible in front of you or not.??. if not, is the light beam behind you ????

2007-10-27 14:50:03 · 4 answers · asked by geraldwarden 1 in Astronomy & Space

Block on Spring without Friction

A spring is stretched a distance of Dx = 40 cm beyond its relaxed length. Attached to the end of the spring is an block of mass m = 8 kg, which rests on a horizontal frictionless surface. A force of magnitude 40 N is required to hold the block at this position. The force is then removed.
a) When the spring again returns to its unstretched length, what is the speed of the attached object?

v0 = m/s

HELP: Apply the work energy theorem: KEfinal - KEinitial = Wspring.
HELP: What is the work done by the spring? How do we find it from the information given?
b) When the spring has returned only halfway (20 cm), what is the speed of the attached object?

v1/2 = m/s

2007-10-27 14:48:22 · 1 answers · asked by cuteeebabygirl 1 in Physics

2007-10-27 14:46:43 · 3 answers · asked by LEITH M 1 in Engineering

What is the molarity of the solution?

2007-10-27 14:44:51 · 3 answers · asked by Foster W 1 in Chemistry

Describe First Hand Account.....................................
As Experienced By Reader.

2007-10-27 14:42:22 · 5 answers · asked by Anonymous in Earth Sciences & Geology

What can you tell about the nature of the iodine molecule? Could it be ionic, polar or nonpolar?

2007-10-27 14:40:37 · 3 answers · asked by Foster W 1 in Chemistry

2007-10-27 14:39:58 · 9 answers · asked by Dzavid N 2 in Physics

can anyone tell me wat the chemical formula for protein is and how the compound is formed?

2007-10-27 14:38:13 · 3 answers · asked by i am what i am 2 in Chemistry

Ahh. I hear from my teacher that sea turtles need fresh water. I put in an assignment that how they get fresh water is by extracting the salt out of salt water and essentially crying it out.
This is what she said:

Your answer to #5 is close, but the freshwater doesn't come from the salt water they drink but from another source they ingest.

__________

Does this mean it comes from it's food?

2007-10-27 14:37:42 · 4 answers · asked by Summie 2 in Biology

^_^

2007-10-27 14:34:43 · 2 answers · asked by Anonymous in Physics

If you answer please leave your name so I can list you as a resource (interview) in my references

2007-10-27 14:34:12 · 4 answers · asked by Anonymous in Earth Sciences & Geology

an example; Yumminium(fake element)

yumminium is so yummy, but it decays your teeth as well as its neutrons!


ive been trying to think of one and i just cant so can anyone here please help me or give me some ideas

2007-10-27 14:30:55 · 4 answers · asked by Anonymous in Earth Sciences & Geology

In Fantasia the airline system is organized in such a way that every city is connected to not more than three others, but even so it is possible to get from one city to another without making more than one change-over.
What is the maximum number of cities in Fantasia?

taken from
http://www.geocities.com/CapeCanaveral/Lab/4661/

2007-10-27 14:30:40 · 1 answers · asked by Mugen is Strong 7 in Mathematics

Why is that when an optically active (R)-2-Bromobutane is added to a solution of NaBr in acetone, the solution gradually becomes optically inactive?

2007-10-27 14:26:22 · 1 answers · asked by Anonymous in Chemistry

with their hairbrained theories by watching Sci-Fi movies or reading Sci-Fi books or something? Have you seen the latest where some scientists is theorizing that the human race will eventually evolve into two species, one beautiful with good physique and smart and the other ugly and small and dumb, did he get that from H.G. Wells or something? Check it out in Yahoo news. What a joke LOL ROF

2007-10-27 14:25:45 · 8 answers · asked by Anonymous in Biology

calculate the number of oxygen present in 50.0 grams of magnesium carbonate trihydrate

2007-10-27 14:25:13 · 5 answers · asked by Anonymous in Chemistry

if not then when is it?

2007-10-27 14:24:12 · 4 answers · asked by keightebby 2 in Physics

Solve for X
( 4 ) / (x^2 + 10x + 24) / =
( 4) / (x + 4 )

2007-10-27 14:16:24 · 3 answers · asked by Anonymous in Mathematics