Physics - August 2007

The field just outside a 4.00 cm radius metal ball is 3.25 102 N/C and points toward the ball. What charge resides on the ball?

My work:

r=4.00 cm --> 4.0x10^-2
E=3.25x10^2

Q=(3.25x10^2)[(4.0x10^-2)^2] divided by (9x10^9)
Q=(325)(.0016)/9x10^9
Q=5.7e-11

I submitted and I am wrong? Hmmm....

2007-08-29 09:53:36 · 7 answers · asked by Jessie L 2

A particle's velocity is described by the function V(t)=k t^2 m/s, where k is a constant and t is in s. The particle's position at t=0 is -9m and at t=3.0s, its position is +9m. Determine the value of constant k. Be sure to include the proper unit.

2007-08-29 09:51:47 · 3 answers · asked by golffan137 3

If The Earth Spins 66000mph and an aeroplane is travelling 500mph OPPOSITE to the direction the earth is spinning and i am walkling 2mph in the SAME direction as the earth is spinning. Doesn't that mean im walking 66002mph and the aeroplane is only travelling 65500mph... Surely that means im faster than the plane? Lol sounds complicated. I worked this out when i was walking my dog with my dad and sister and saw an aeroplane overhead :D

2007-08-29 09:12:05 · 18 answers · asked by Nathaniel Wolfgang Amadeus 2

The arm of the catapult is R=10ft long,
http://www.knightsedge.com/medieval-weapons/medieval-catapult-4804.jpg
and starting from initial horizontal position it acclerates projectile at the rate s=100 rad/s².
The crew can regulate the angle at which projectile is relesead.

g = 32 ft/s², no air resistance

2007-08-29 08:58:33 · 8 answers · asked by Alexander 6

How long will it be in the air?

2007-08-29 07:51:43 · 5 answers · asked by Wonder 2

2007-08-29 07:06:14 · 15 answers · asked by Anonymous

How long will it be in the air?

2007-08-29 06:57:24 · 4 answers · asked by Wonder 2

Germanium is a(n)

alkali metal.

halogen.

noble gas.

metalloid.

2007-08-29 06:44:35 · 4 answers · asked by Anonymous

A neutron strikes a target nucleus of U235, which then releases several neutrons. What kind of reaction is taking place here?

2007-08-29 06:44:17 · 6 answers · asked by Anonymous

Radon-222 has a half-life of 3.8 days. How many half-lives will it take for an 11 g sample to be reduced to 2.75 g?

2007-08-29 06:43:39 · 1 answers · asked by Anonymous

The splitting of the nucleus of an atom to obtain energy is called:

2007-08-29 06:42:05 · 11 answers · asked by Anonymous

Why is it that when I've got money, I have no time to spend it. But when I've got time to kill, I've got no money with which to do it?

2007-08-29 05:23:22 · 4 answers · asked by Johnny Law III 3

Small asteroids and other objects can be found in many shapes.

However, at some mass, gravity will automatically shape the object into a sphere. What is this point (like what mass or when does this happen)? And why?

2007-08-29 05:20:23 · 6 answers · asked by ch_ris_l 5

lol just a little dumb question

2007-08-29 04:44:58 · 5 answers · asked by Noles 4

Three forces are applied to an object. Force 1 has a magnitude of 27.0 newtons (27.0 N) and is directed 30.0° to the left of the +y axis. Force 2 has a magnitude of 18.0 N and points along the +x axis. What must be the magnitude and direction of the third force 3 such that the vector sum of the three forces is 0 N? (force 3 points south of west)

2007-08-29 04:40:49 · 3 answers · asked by Anonymous

totel travel time for me is 2 sec.

2007-08-29 04:24:31 · 5 answers · asked by Anonymous

2007-08-29 04:09:10 · 4 answers · asked by gokulraj 1

Would it not run more efficiant if i removed the intake hose from pulling the warmer air from outside, and have it pull the colder inside air? Danby company says no. Why?

2007-08-29 04:05:59 · 4 answers · asked by Dan 2

ETHER
Current mood: grateful
Category: Religion and Philosophy


THE EATHER OF SPACE

Eather of space probley from I burn,

a material substance of more suitable kinds than visible bodies, supposed to exist in those parts of space which are apparently empty.: so thus begins the article "Ether" written for the ninth edition of the encyclopedia Britannica by James Clark Maxwell. The derivation seems to indicate some connexion in the mens minds with the idea of fire: the other three elements earth Water Air representing solid, liquid and gaseous conditions of ordinary matter respectively. The name Ether suggests a far more subtle or penetrating and ultra material kind of substance.

Newton explains the term for the medium which fills space - not only space which appears to be empty, but space also which appears to be full; for the luminiferous ether must undoubtedly pebetrate between the atoms - must exist in the pores so to speak - of every transparent substance, else light could not travel through it.

2007-08-29 02:50:34 · 4 answers · asked by Anonymous

2007-08-29 01:57:20 · 6 answers · asked by Anonymous

Your manager is very please with your presentations and being able to show your calculations in a detailed fashion. He has asked that you help him prepare for the upcoming company summit. Before you get together, he has asked that you give him a little review on polynomial functions and how you would apply them to everyday use. You have thought about the different methods in showing him the different methods used in calculating the functions and have drawn up an action plan.

To exercise your skills, you are to perform the following using different tools available to you (e.g. Excel spreadsheet, graphing calculator, etc.) and write and explanation on your findings:

The graph of: f(x)= 0
The graph of: f(x) = a0 , where a0 ≠ 0
The graph of: f(x) = a0 + a1x , where a1 ≠ 0
For each of the three above:

What does the graph look like- describe the x placement
What is the graph function called?
Give an example of a number you could place in for the variable x, and describe the shift from the original graph. Remember to note what your value you are calculating for the variable x.

2007-08-28 17:51:45 · 1 answers · asked by Regina F 1

Water is the most important substance on Earth. One reason for its usefulness is that it exists as a liquid over a wide range of temperatures. In its liquid range, water absorbs or releases heat directly in proportion to its change in temperature.

Consider the following data that show temperature of a 1,000 g sample of water at normal atmospheric pressure as a function of heat supplied. A kJ can simply be thought of a unit of heat.


Temperature Heat Supplied
0 oC 0 kJ
10 oC 42 kJ
30 oC 126 kJ
50 oC 209 kJ
80 oC 335 kJ
99 oC 414 kJ
100 0C 420 kJ

Based on these data, please supply the following:
1. Provide a graph of the data. Is the graph sufficiently linear to allow prediction of heat supplied versus temperature in the range of 0–100 oC?
2. If so, use Microsoft Excel to provide an equation that relates heat, y, supplied to temperature, x, in the range of 0–100 oC.
3. Are the results consistent with the expected equation, heat = (1.00 cal/g oC

2007-08-28 17:43:35 · 1 answers · asked by Regina F 1

Okay, i just started college, and was forced to take Physics 2A in order to be able to take 1A later.

Now i am not new to Physics, i learned and loved the subject for an entire year and scored a 4 on the AP exam, so know that i am not an idiot who needs to start at base-level, my school just didnt care and made me take it anyway

so first day's homework assignment was easy, but i couldn't help but notice everything was in American units....

WHY?

Why use Empirical? it is pointless and useless, metric is easier to convert within it's own system, if you go on an international level and measure things in ft, you will get laughed at and to top it all off, Metric is not so confusing when it comes to weight and mass.

Does anyone know why my professor is teaching in Empirical?

Do all college professors teach Empirical?

2007-08-28 17:30:55 · 3 answers · asked by Jay 3

I know that in Archimedes' principle, the buoyant force is equal to the weight of the fluid displaced by the object. Since the object will sink until it has displaced fluid equal to its weight, why isn't the principle that the bouyant force is equal to the weight of the object? Isn't this true:

weight of object = weight of displaced fluid = buoyant force?

2007-08-28 17:27:30 · 5 answers · asked by LaDeeDa 2

hi, i understood these problems during class, but now that i'm doing the hw, i'm completely lost.

question 1: According to a rule-of-thumb, every five seconds between a lightning flash and the following thunder gives the distance of the storm in miles. Assuming that the flash of light arrives in essentially no time at all, estimate the speed of sound in m/s from this rule.

question 2: A horse canters away from its trainer in a straight line, moving 130 m away in 14.0s. It then turns abruptly and gallops halfway back in 4.8s. Calculate (a) its average speed and (b) its average velocity for the entire trip, using "away from the trainer" as the positive direction.

question 3: An airplane travels 2100 km at a speed of 800 km/h and then encounters a tailwind that boosts its speed to 1000 km/h for the next 1800 km. What was the average speed of the plane for this trip?

I already know the answers, but I need help figuring out to work the problems.

2007-08-28 17:25:32 · 1 answers · asked by kolipjh126 2

An object is thrown vertically upward such that it has a speed of 25 m/s when it reaches two thirds of its maximum height above the launch point. Determine this maximum height.

Can someone please explain HOW to do this? I don't just want the answer. Is there an equation I need to use orr .. ? I've been trying to figure this out and can't seem to get a correct answer :(

Any help is greatly appreciated!

2007-08-28 17:04:39 · 4 answers · asked by music123 1

This was part of a homework assignment for my Physics class. I was wondering if anyone could please help me solve this by providing at least some background guidance:

(Fx is F sub x and Fy is F sub y)

The x and y components of a force are Fx = 12N and Fy = -15N, respectively. Determine the magnitude and direction of F.

Thanks! ^_^

2007-08-28 16:24:32 · 4 answers · asked by Erwy 2

I need to know how to add and subtract measurements. I left my book at school, and I can't remember at the top of my head.

For example: 6.20 x 10 to the 5th power(sorry, I don't know how to type exponents) mm + 7.20 x 10 to the 6th power mm(No, this isn't a homework problem I want you to do for me. I just need to know the steps on how to do it.)

If you can help in any way, please do share your knowledge. It'd be greatly appreciated!!

2007-08-28 16:18:30 · 4 answers · asked by Dani Marie 3

2007-08-28 15:49:22 · 4 answers · asked by OMG. 2

Some postings in other groups insist that during certain periods of acceleration during his trip a traveller insists that his twin sister is physically ageing at faster or slower rates than she was before he commenced his trip on the basis that this is what he determines on the basis of his calculations based on the Lorentz equations.

I am trying to find out if this concept is 'conventional wisdom' in the scientific world?

2007-08-28 15:48:22 · 5 answers · asked by cos 1