Science & Mathematics - 5 October 2007

What are (a) the charge and (b) the charge density on the surface of a conducting sphere of radius 0.14 m whose potential is 200 V (with V = 0 at infinity)?

Some work plesae, numbers, equations, etc.

2007-10-05 14:04:40 · 1 answers · asked by Anonymous in Physics

You and your friend are playing tennis. Your friend lobs the ball high into the air, hitting it 3 feet above the court with an initial vertical velocity of 40 feet per second. You back up and prepare to hit an overhead smash to win the point.
a.) Use the model h=-16t^2 + v0t + h0 to write an equation giving the height of the lobbed tennis ball as a function of time.
b.) At what time t does the ball reach its maximum height above the court? What is the maximum height?
c.) If you plan to hit the smash when the ball falls to a height of 8 feet above the court, how long do you have to prepare for the shot?
d.) If you plan to hit the smash when the ball is between 6 feet and 9 feet above the court (inclusive) what are your possible preparation times?
e.) Suppose you hit the smash when the ball is 8 feet above the court. It takes 0.1 second for the ball you smashed to hit the court on your friend's side of the net. What was the ball's initial velocity coming off your racket?

THANKS!

2007-10-05 14:01:51 · 2 answers · asked by pigosaurus 1 in Mathematics

What is the magnitude of the electric field a the point (3.00i – 200j + 400k) m if the electric potential is given by V = 2.00xyz^2, V is in Volts and x, y, and z are in meters.

I'm lost need some work!

2007-10-05 13:58:59 · 1 answers · asked by KwadwoT 1 in Physics

a/b=c/d


Also, how would you solve for b in this case:

5/2=1/2(b-c)

2007-10-05 13:57:17 · 9 answers · asked by Anonymous in Mathematics

l velocity of the car? Answer in units of m/s.

b) How far does the car travel in this time interval? Answer in units of m.

2007-10-05 13:56:10 · 5 answers · asked by americasnextopfashiondesigner 2 in Physics

2007-10-05 13:53:52 · 4 answers · asked by meteor showers 1 in Astronomy & Space

I live in KS...... See it everyday at about 6AM... eastern sky... Halfway up Brightest star in sky....Just curious to see if anyone can tell me

2007-10-05 13:50:52 · 3 answers · asked by Anonymous in Astronomy & Space

I had a shot in my upper arm yesterday. Today it hurts..WHY?

2007-10-05 13:50:30 · 6 answers · asked by S i r i 1 in Medicine

Describe simple chemical tests that would enable you to distinguish between the following sets of compounds. Write equations for any chemical reactions:

(a) dinitrogen monoxide (nitrous oxide), ammonia, and nitrogen

(b) carbon monoxide, carbon dioxide, and nitrogen monoxide

(c) dilute hydrochloric acid, deuterium oxide, and hydrogen peroxide solution

2007-10-05 13:48:16 · 1 answers · asked by Hammad A 1 in Chemistry

i have a hard time taking blood pressure...
I am a newbie...pretty green..
any tips?

2007-10-05 13:48:02 · 7 answers · asked by S i r i 1 in Medicine

for a research paper...

2007-10-05 13:45:02 · 10 answers · asked by Ana O 1 in Biology

Write balanced chemical equations or formulas (annotated where appropriate) for each of the following descriptions:

(i) oxygen undergoes photodissociation in the upper atmosphere;

(ii) the nitric oxide molecule undergoes photoionisation in the upper atmosphere;

(iii) ozone is formed in the upper atmosphere;

(iv) ozone is destroyed in the upper atmosphere;

(v) nitric oxide catalyses the decomposition of ozone in the stratosphere;

(vi) nitrogen dioxide is an acidic oxide and forms an acid solution in water;

(vii) sulfur dioxide emissions from industrial sources cause acid rain;

(viii) why rainwater is naturally acidic, even in the absence of any polluting gases

(ix) despite the answer in (viii), why the pH of unpolluted sea water is about 8.2

(x) why nitrogen is not, but carbon dioxide is, a 'greenhouse gas'

2007-10-05 13:44:32 · 1 answers · asked by Hammad A 1 in Chemistry

I want to buy rock by the cubic yard instead of by the ton and would like to know how many pounds is in a cubic yard

2007-10-05 13:40:09 · 3 answers · asked by outlaw1 1 in Engineering

Is there any value of n other than 1, 2, and 4, such that n^n+1 is a prime?

2007-10-05 13:39:38 · 6 answers · asked by swimgirl273 2 in Mathematics

2007-10-05 13:37:54 · 8 answers · asked by pretty36 1 in Physics

Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 5.0 kg projectile from rest to a speed of 3.8 103 m/s. The net force accelerating the projectile is 4.6 105 N. How much time is required for the projectile to come up to speed?
____ s

2007-10-05 13:36:37 · 1 answers · asked by Antonio E 1 in Physics

answer and problem work.

2007-10-05 13:33:17 · 13 answers · asked by Anonymous in Mathematics

hydrogen was (or is) the initial element in the appearance of matter in the Cosmos? Has anybody postulated on how or why ('God doesn't throw dice' - Einstein) the first hydrogen atom (or its components) appeared out of 'nothingness' preceding the Big Bang, of couirse? I understand the religious implications of this question, but observe that 'everything' He did, seems to eventually prove logical and with a scientific basis.

2007-10-05 13:30:51 · 2 answers · asked by te144 7 in Physics

2007-10-05 13:30:31 · 3 answers · asked by . 1 in Mathematics

This is a college-level course, and I really need to know how far back I need to go to teach myself how to get there. I'm stuck, I can't go any further in college until I pass this course, which I have already taken twice. I need to know the name of a pre-requisite, or a text...something...hellllp!

2007-10-05 13:28:31 · 7 answers · asked by tlwdthn 1 in Mathematics

4(2x+1)=27+3(2x-5)

2007-10-05 13:27:24 · 6 answers · asked by Anonymous in Mathematics

Find the work done by force F = -3j (pounds) applied to distance that moves on a line from point (1,3) to (4,7). Assume distance is measured in feet. I just started learning vectors so I'm not sure if the following is correct:
Would the distance be (4-1, 7-3) = 3i + 4j?
Since W = F•D, is the answer (-3j) • (3i + 4j) = -12 foot-pounds? Thanks in advance

2007-10-05 13:24:07 · 5 answers · asked by MathGuy 6 in Mathematics

If x + 1/x = 2, what is the value of x^2 + 1/x^2 ?

When possible, with explanation please.
Thanks in advance!

2007-10-05 13:23:45 · 6 answers · asked by Anonymous in Mathematics

Any ideas in cu.ft. or gallons?

2007-10-05 13:23:23 · 2 answers · asked by Freddy123 2 in Earth Sciences & Geology

(a) find all zeros of the function (b) write the polynomial as a product of linear factors, (c) use your factorizatoin to determine the x-intercepts of the graph of the function.

#27.) f(x)= x^2-14x+36

I'm not sure how to work it out so any help would be very, very much appreciated. Person with most answers and worked out understandably will receive the 10 points. Thanks all, for trying, and helping my future!

2007-10-05 13:23:11 · 1 answers · asked by Anonymous in Mathematics

Do you remember it? It was so fun and at the end it turns out the alien and your ship was the bad guy using rad gravity to collect all the items for himself. I was a little kid back then and that just blew me outta the water when that happened. Much like how darth vader turned out to be luke skywalkers dad.

http://en.wikipedia.org/wiki/The_Adventures_of_Rad_Gravity

2007-10-05 13:21:32 · 1 answers · asked by Anonymous in Astronomy & Space

hiii.
basically, i need a science fair experiment and i want to do one i am passionate about.
some of my interest include:
swimming, photography, music, FASHION (main idea)


so if anyone can come up with an experiemnt i can do with one of those particular catergories that would be amazing

:]

<33

2007-10-05 13:14:23 · 2 answers · asked by tarea 2 in Other - Science

A. Red
B. Rose

2007-10-05 13:10:22 · 2 answers · asked by *:)* 1 in Botany

3x + 7 = 5x - 11

2007-10-05 13:09:04 · 8 answers · asked by Lucia I 1 in Mathematics

Could you please show me step by step your result.

2007-10-05 12:59:00 · 3 answers · asked by xxxladyxxx 1 in Chemistry