Physics

Approximately what is propagation delay in a 4km optical fibre

Is it 3*10^8/4000? If not what? Thanks.-Depends on the refractive index of the fibre.Say it is 1.5. Speed of light in fibre = 3x10^8 / 1.5 = 2x10^8 m/s Time = distance /speed = 4000 / (2x10^8) = 2

Physics SHORT ANSWER do not understand..... PLEASE HELP ASAP DUE tonight

42. How will you charge a metal sphere by the process of induction? 43. State and explain Coulombs law. 44. Define electric potential energy and electric potential at a point in an electric field.

Springs, Physics exercise

Help me with this physics exercise http://subefotos.com/ver/?a16b02ac5b93a1d6eb029c2d86661e29o.jpg The answer is 45 seconds but I do not know how to solve it-Hello you can not mean that the answer

What is the state of matter known as super-solidity

helium-http://en.wikipedia.org/wiki/Supersolid

What is the laser of Ms. Hui Cao inspired by bird feathers (color effect)

A new kind of laser captures light just like some colorful bird feathers. The device mimics the nanoscale structure of colorful feathers to make high-intensity laser light with almost any color. Laser

Wave lengths of these electromagnetic waves

I need the wavelengths of the following Radio waves, Microwaves, Infrared waves, Visible light waves, Ultraviolet waves, X-rays, and Gamma rays.I do not need a big complicated answer.ALL I am looking

Simple Harmonic motion (physics help)

A vertical spring stretches 3.9cm when a 10 gram object is hung from it. The object is replaced with a block of mass 25g that oscillates up and down in a simple harmonic motion. If you can do the pro

Does black hole entropy increases as it's mass increases

If so, are they proportional to some constant?-Well, some of usbase our understanding on provable, testable science instead of stupid , retarded ,bronze-age fairy tales written by ignorant savages.The

Does the "negative" potential energy of the earth's gravity decrease it's mass

Is it to think that the earth mass is somewhat less than sum of its parts due to the increase in potential energy of the earth due to gravity? If so, where does that potential energy go if it goes an

Which of the following is true about a zero decibel sound level

A) is nonsense B) is just at the threshold of hearing C) has zero amplitude D) none of the above-B. 0dB sound level is 10^-12W/sq.m - about the threshold of hearing.-Decibel = 10 log(Intensity1/intens

Questions on black holes...will you describe your answers please

Assuming that black holes have entropy as per hawking then does it follow that so too would white holes? Would spontaneous symmetry breaking be an example of light/white body radiation? What is the

Doppler Effect and a Trumpet

Aperson on a railroad car blows a trumpet sounding at 485.0 Hz. The car is moving toward a wall at 21.0 m/s. assume the speed of sound is 343.0 m/s Calculate the frequency of the sound as received at

What is the difference between Natural and Forced Convection

The question is: using physical parameters of the fluid distinguish clearly between: i) Natural convection ii) Forced convection Thanks for any help!-Natural convection is the movement that is power

ANOTHER PHYSICS QUESTION INVOLVING MECHANICAL ADVANTAGE,POTENTIAL, INPUT OUTPUT FORCE! PLZ HELP!

Hey sorry i know there are a lot of questions but please if you can then help me out a bit! thanks ill really appreciate it! and its multiple choice so please choose ONLY ONE. thanks. 1) a nutcracker

Was albert einstein a lefty

he lived only sixty years ago: why is it so difficult to determine whether he was right or left handed?-If you look at him playing violin, youll see him playing as a righty.The same is true if you see