Physics - March 2007

2007-03-16 12:30:25 · 11 answers · asked by Anonymous

i know that a large mass puts a dent in the fabric of space and causes things to move toward it. but if its just a thin layer of the fabric of space, how do you explain the tilt in orbits.and isnt space 3 dimensional? and if the universe is supposed to be a sphere, whats inside? could be a driving mechanism for gravity. or does gravity travel in waves?

2007-03-16 12:22:51 · 4 answers · asked by 22 4

There is a 50 degree angle between the horizontal and the wire and a 30 degree angle between the horizontal and the beam.
Calculate the magnitude of the tension in the wire. Calculate the magnitude of the horizontal and vertical components of the force that the wall exerts on the left end of the beam.

2007-03-16 12:06:17 · 3 answers · asked by Fuzz 1

An air filled spherical capacitor is constructed with inner and outer shell radii of 6.5 cm and 13.1 cm, respectively. The coulomb constant is 8.98755 X 10^9.
1. Calculate the capacitance of the device. Answer in units of pF.
2. In addition, what potential difference between the spheres results in a charge of 31.4 micro C on the capacitor? Answer in units of kV.

I tried using C= Q / Vab = 4πEo*(r_a*r_b / (r_b - r_a) but that didn't work.

2007-03-16 12:02:52 · 4 answers · asked by mcgrady111 1

A sphere of mass 20 kg and radius 2 m starts from rest and rotates with a constant
angular acceleration of 4 rad/s2 about a fixed axis through its center. After 4.8 s, what
is the kinetic energy (in kJ) of the sphere?

W = 4
M = 20
R = 2

Krot = 1/2 I W^2, I for a sphere 2/5M*R^2
Replacing I in the equation, Krot = 1/2(2/5M*R^2)W^2
The answer should be 5.9 in kJ. Where did I go wrong? :(

2007-03-16 11:37:02 · 2 answers · asked by Mark4505 2

The question, "Why is the sky blue?" must have been asked at least a hundred times by now on Y!A, no matter how many times it's been answered. Is there something about blue skies that strikes a deep chord or what?

2007-03-16 11:36:11 · 5 answers · asked by Scythian1950 7

I don't believe Einstein was correct...I just don't Tesla didn't think he was right either so there...
I'm sorry Einstein but I refuse to beleive that in the future we will have to travel for TEN WHOLE YEARS to get to the center of the galaxy

Anybody else disbelieve his theory if so please tell me why

2007-03-16 11:25:01 · 12 answers · asked by ? 2

Consider a 2.35 m by 10.0 m housing wall, with a section shown in the diagram.
A builder has the choice of using 1.5 in. by 3.5 in. studs (at $2.30 each; R=4),
or 1.5 in. by 5.5 in. studs (at $4.45 each; R=7). The studs are spaced with a center-to-center distance of 40 cm.
The thinner wall can accommodate R=12 insulation (at $3.30 per m2), whereas the thicker wall can accommodate R=38 insulation (at $6.25 per m2).
Assume that the house is to be built in an area where the average difference between the inside and the outside temperature is 12.0 °C. If the cost of heating is $0.10 per kWh, how long will it take for the homeowner to recoup the extra costs associated with building the better insulated wall? (Enter the number of days.)

2007-03-16 11:20:56 · 2 answers · asked by 2 2 1

would you eventually meet Marie and Cherry Curie going the other way?

2007-03-16 11:00:37 · 3 answers · asked by Anonymous

Heres a problem I struggle with. If time always existed in the void
then creation is impossible because it would of taken forever to happen (to get to a specific point in time from eternalty). If time only existed post-creation and during then no motion could take place to start its process.

2007-03-16 10:58:29 · 9 answers · asked by Anonymous

2007-03-16 10:49:16 · 1 answers · asked by maur19852000 1

How can I determine the force of a magnet, and how far the field extends? Does the force decrease with distance?

2007-03-16 10:37:30 · 4 answers · asked by Anonymous

say you could tunnel through the earth north to south pole and be able to drop a object through the centre of the earth . how long would it take for it to travel through. no saying it would melt at the middle, as you have dropped it through a tunnel thanks

2007-03-16 10:37:19 · 13 answers · asked by Anonymous

E=mc2 means Mass x Speed o' light = Energy
Does that mean if you go faster than the speed of light you turn into energy?
If not please explain what it does mean and why.
and if it does please explain why

2007-03-16 10:37:04 · 8 answers · asked by ? 2

A 145 g baseball is dropped from a tree 8.0 m above the ground.(a) With what speed would it hit the ground if air resistance could be ignored?
(b) If it actually hits the ground with a speed of 8.40 m/s, what is the magnitude of the average force of air resistance exerted on it?

2007-03-16 10:34:59 · 2 answers · asked by Anonymous

They have destructive interference right? So I've been thinking about building a machine that you can set to a lights electromagnetic frequency have it destroy the waves and then have it create a field of darkness. Do you think this is possible? If it is has anybody ever thought of this before? please let me know

oh and if you build one at least leave a based on Drake Saratoga's Idea's in the instruction manual

2007-03-16 10:20:28 · 3 answers · asked by ? 2

A 1000 kg car rolling on a horizontal surface has speed v = 45 km/h when it strikes a horizontal coiled spring and is brought to rest in a distance of 2.2 m. What is the spring stiffness constant of the spring?

2007-03-16 10:17:35 · 2 answers · asked by Anonymous

If you're driving towards the sun late in the afternoon, you can reduce the glare from the road by wearing sunglasses that permit only the passage of light that's....

A- Polarized in a vertical plane.
B- Polarized in a horizontal plane.
C- Dispersed in a vertical plane.
D- Dispersed in a spherical plane.

2007-03-16 10:11:44 · 5 answers · asked by Anonymous

there's a fly (one that works ;) ) just in front of you...

and also another identical (clone or something) outside the bus at same sort of position.....

Bus starts moving forward....

How come (assuming both flies just hovering) the fly inside the bus stays in same place but fly outide bus has gone way behind you...

How come fly inside bus has not been smashed against inside windscreen

And also how come a third fly minding his/her own business just outside up in front of bus gets smashed on outside of front bus window??

2007-03-16 10:00:47 · 11 answers · asked by mona 1

instead of saying, the electron starts from the cell and..passess the switch...how can u make it into a newspaper article which does not include electrons but the concept of a electron travelling in a circuit is in the newspaper article.

2007-03-16 09:59:59 · 1 answers · asked by Patel s 1

A ball is attached to a horizontal cord of length L whose other end is fixed
(a) If the ball is released, what will be its speed at the lowest point of its path? (Answer using g for acceleration due to gravity and L as necessary.)
(b) A peg is located a distance h directly below the point of attachment of the cord. If h = 0.86 L, what will be the speed of the ball when it reaches the top of its circular path about the peg?

2007-03-16 09:56:56 · 4 answers · asked by Anonymous

Self explanitory.

2007-03-16 09:54:03 · 2 answers · asked by Super W 1

A 60 kg trampoline artist jumps vertically upward from the top of a platform with a speed of 3.5 m/s. (Ignore small changes in gravitational potential energy.)
a)How fast is he going as he lands on the trampoline, 3.0 m below? (This is 8.43 m/s)
(b) If the trampoline behaves like a spring with spring stiffness constant 5.2 104 N/m, how far does he depress it?

2007-03-16 09:50:04 · 3 answers · asked by Anonymous

the formula is magnitude of buoyant force = weight of fluid displaced
or F of b = f of g times m
What is f of g?

2007-03-16 09:40:43 · 3 answers · asked by Fiamanillah 3

I know that as light enters a medium (from a vacuum) its wavelength is reduced and its frequency remains the same, resulting in a slower speed. But, can anybody explain to me exactly how the light is interacting with the atoms or molecules of the medium (whatever medium is preferred for an easy to understand explanation) in order for this to occur.

2007-03-16 09:37:49 · 4 answers · asked by eazylee369 4

A 11 pF capacitor is connected across a 71 V source. What charge is stored on it? Answer in Coulombs

2007-03-16 09:35:56 · 2 answers · asked by kpm0729 1

* if you are completely addicted to PhysicsNow.com.

* if you have no life - and you can PROVE it mathematically.

* if you enjoy pain.

* if you know vector calculus but you can't remember how to do long division.

* if you chuckle whenever anyone says 'centrifugal force.'

* if you've actually used every single function on your graphing calculator.

* if it is sunny and 70 degrees outside, and you are working on a computer.

* if you always do homework on Friday and Saturday nights.

* if you have a pet named after a scientist.

* if you laugh at jokes about mathematicians.

* if when your professor asks you where your homework is, you claim to have accidentally determined its momentum so precisely, that according to Heisenberg it could be anywhere in the universe.

* if the 'fun' center of your brain has deteriorated from lack of use.

* if you'll assume that a 'horse' is a 'sphere' in order to make the math easier

2007-03-16 09:15:36 · 6 answers · asked by Anonymous

I have 5 questions in all, here are the links to them:

http://i152.photobucket.com/albums/s167/gt_badone/31-58.jpg

http://i152.photobucket.com/albums/s167/gt_badone/31-59.jpg

http://i152.photobucket.com/albums/s167/gt_badone/31-60.jpg

http://i152.photobucket.com/albums/s167/gt_badone/31-61.jpg

http://i152.photobucket.com/albums/s167/gt_badone/31-98.jpg

I need formulas more than answers, if you are going to give me answers (don't need solution) be sure to provide formulas!

2007-03-16 08:47:29 · 1 answers · asked by gt_badone 1

according to light curvature

2007-03-16 08:46:28 · 6 answers · asked by Anonymous

2007-03-16 08:26:56 · 5 answers · asked by Sexxi Nera 1