Physics - March 2007

why 1eV = 1.6 x 10^-19 J? thx

2007-03-06 22:11:52 · 2 answers · asked by Anonymous

2007-03-06 21:48:37 · 6 answers · asked by Pratibha P 1

I have started physics at University level and yet I have never done it before. I need some very simplified help which explains some of what I need.

2007-03-06 21:21:05 · 1 answers · asked by blue_kat_88 1

My Second year college project am investigating attenuation of visible light....

2007-03-06 21:10:33 · 2 answers · asked by CrazBrains 1

fired from a gun

2007-03-06 20:16:09 · 8 answers · asked by shiva6174 1

Planet X rotates in the same manner as the earth, around an axis through its north and south poles, and is perfectly spherical. An astronaut who weighs w on the earth weighs w_1 at the north pole of Planet X and only w_2 at its equator. The distance from the north pole to the equator is L, measured along the surface of Planet X.

a) How long is the day on Planet X? Use g for free fall acceleration
b) If a m satellite is placed in a circular orbit h above the surface of Planet X, what will be its orbital period? Take free fall acceleration to be g

2007-03-06 20:06:59 · 1 answers · asked by Paul Wall 2

When in orbit, a communication satellite attracts the earth with a force of F and the earth-satellite gravitational potential energy (relative to zero at infinite separation) is - U

a) What is the satellite's altitude above the earth's surface?
b) What is the mass of the satellite?

2007-03-06 20:03:55 · 3 answers · asked by Paul Wall 2

A uniform rod of mass m_1 and length L rotates in a horizontal plane about a fixed axis through its center and perpendicular to the rod. Two small rings, each with mass m_2, are mounted so that they can slide along the rod. They are initially held by catches at positions a distance r on each side from the center of the rod, and the system is rotating at an angular velocity w (omega). Without otherwise changing the system, the catches are released, and the rings slide outward along the rod and fly off at the ends.

a) What is the angular speed of the system at the instant when the rings reach the ends of the rod?
b) What is the angular speed of the rod after the rings leave it?

2007-03-06 19:58:24 · 4 answers · asked by Paul Wall 2

I read an article that said electric signals can be transmitted at least four times faster than the speed of light. In an experiment the peak of an electric wave could be transmitted at 4 billion km/h (if i m not mistaken) but Einstein's theory would be preserved because it says that "no information could travel faster than light" (???) I don't understand this! Isn't "information" that electric signal that goes faster than light??

One of this articles is here:
http://www.newscientist.com/article.ns?id=dn2796

Can anyone please make clear what that stuff about "information" is??

2007-03-06 19:25:33 · 5 answers · asked by Anonymous

I am working on this problem for physics. But I frankly think that this is impossible.. even though it wont be. Here is the problem:

The four tires of an automobile are inflated to a gauge pressure of 2.0x10^5 Pa. Each tire as an area of 0.024 m^2 in contact with the ground. Determine the weight of the automobile.

The first thing that came to my mind was using P=F/A and fin F so I could find the force and then the mass.. but that didn't worked. I would gladly appreciate if anybody can answer and explain how the process work. Thanks :)

2007-03-06 19:05:47 · 4 answers · asked by luisjopr 1

Hydrostatics and hydrodyamics?
1. In a hydraulic pressure the small cyclinder has a diameter of 5 cm ,while the large piston has a diameter of 10 cm.Neglecting friction,if a force of 15 N is applied to the small piston.what is the force on the large piston?

2. A cube 1 meter on one side floats half submerged in a tank of oil( specific gravity of 0.8) a.) What is the buoyant force exerted by oil acting on the cube? b.) If a piece of metal is placed on top of the cube, how heavy should the metal be in order to just submerge the cube completely?

3. a horizontal pipe 5 cm in radius at one end gradually decreases in size so that it is 2 cm in radius at the other end.the pipe is 5 m long.Water is pumped into the large end of the pipe at a speed of 2 m/s and a pressure of 8x10^5 N/m^2.Determine the speed and pressure of the water at the pipe's small end.

please help to sove this problem,i really appreciate your help

2007-03-06 18:49:17 · 3 answers · asked by khenzkey_wawa08 1

when illuminated with green light
when illuminated with yellow light
when illuminated with blue light
when illuminated with red light
when illuminated with white light..... select all that apply.....

2007-03-06 18:42:38 · 9 answers · asked by delkkis 1

if this is true, than einsteins theory s wrong. one or the other, or supprise me.

2007-03-06 18:38:38 · 8 answers · asked by Sanwi 3

2007-03-06 18:23:51 · 3 answers · asked by delkkis 1

Fluids and dynamics?
1. Water flows through a 2 cm opening in the side of a tank. If the opening is 8 m below the surface of the water,what volume of a water would escape from the tank per minute?If a stream of water escapes from another hole 2 m above the base of the tank and strikes the ground at a horizontal distance of 25 m.How far below the surface of the water is the hole?

2. A sphere 1 m in diameter floats half submerged in a tank of oil( Sg = 0.80). a.) What is the upward force acting on the sphere? b.) What is the minimum weight of an anchor w/ a density of 20,000 N/m^3 that will be required to submerge the sphere completely? c.) What minimum weight of a body placed on the top of the sphere will be required to just submerge sphere completely?

2007-03-06 18:23:37 · 2 answers · asked by jhen_hidaka 1

2007-03-06 18:23:17 · 5 answers · asked by Pirate of the Bassein Creek 4

2007-03-06 17:44:37 · 15 answers · asked by shazi k 1

Electrons in a television's CRT are accelerated from rest by an electric field through a potential difference of 2.5kV. In contrast to an oscilloscope, where the electron beam is deflected by an electric field, the beam is deflected by a magnetic field.

What is the speed of the electrons?

The beam is deflected by a perpendicular magnetic field of magnitude 0.80T. What is the acceleration of the electrons while in the field?

What is the speed of the electrons after they travel 4.0mm through the magnetic field?

What strength electric field would give the electrons the same magnitude acceleration as in the acceleration of the electrons while in the field?

Why do we have to use an electric field in the first place to get the electrons up to speed?

Why not use the large acceleration due to a magnetic field for that purpose?

2007-03-06 17:22:15 · 2 answers · asked by Sir Guitarist 2

2007-03-06 17:22:09 · 4 answers · asked by jeheil 1

2007-03-06 17:15:23 · 3 answers · asked by jeheil 1

"matter is nether created nor destroyed" who came up with this law?

2007-03-06 17:11:12 · 4 answers · asked by eyeballcollecter 1

weight is mass*gravity

2007-03-06 17:08:28 · 4 answers · asked by rohit_gupta322 2

I read a lot about it in other books yet they all explain it over the top and never with ellaborate reasons of why certain things happen?? Does anyone know of any good book about this subject???

2007-03-06 16:57:51 · 3 answers · asked by feelingtherain 2

2007-03-06 16:52:54 · 3 answers · asked by sakendo 2

2007-03-06 16:51:42 · 8 answers · asked by sakendo 2

A ski tow operates on a slope of angle 14.7 of length 260 . The rope moves at a speed of 11.5 and provides power for 55.0 riders at one time, with an average mass per rider of 75.0 .

Estimate the power required to operate the tow.

Been stuck on this problem for an hour maybe, any ideas?

2007-03-06 16:31:05 · 2 answers · asked by Dathan C 2

2007-03-06 16:18:54 · 20 answers · asked by paru p 1

Why or why not?!

2007-03-06 16:17:52 · 3 answers · asked by Meh... 3

2007-03-06 16:06:21 · 3 answers · asked by sheera 1

I am really going nuts trying to figure out how to do this physics question... I'll reward best answer points to whomever will not only get the answers but explain to me how and why they got them...

(a)What is the tangential acceleration of a bug on the rim of a 10-in. diameter disk if the disk moves from rest to an angular speed of 78 rev/min in 3.0s.? (b) When the disk is at its final speed, what is the tangential velocity of the bug? (c) One second after the bug starts from rest, what are its tangential acceleration, centripetal acceleration and total acceleration?

2007-03-06 15:50:35 · 1 answers · asked by Anonymous