Recent content by wikidrox

What happens when you increase the frequency of the light incident on a metal surface? Does it increase the threshold frequency for the emission of photoelectrons? Does it increase the Kinetic energy of some energetic photoelectrons? I can't figure this out.

I am having trouble answering this question. When violet light is beamed onto a negative electrode in a photo-tube, a current begins to flow in the tube. Consider the following forms of electric radiation : Blue Light; infrared radiation; ultraviolet radiation. Which of these must also...

1. I need some clarification that I answered this question properly What is the wavelength of an electron of energy 5.0 eV? Would I just use E=mc^2 to find the mass and then wavelength = h / mv to find the wavelength? 2. This question is also giving me problems By what potential...

Shoot! I think I did it wrong. What would the speed of sound be at 20 degrees? I just thought the speed of sound would be the same as the speed of light. I guess I was wrong.

I just need a hint on this. 2 plates of a capacitor hold +1500 C and -1500 C of charge, respectively, when the potential difference is 300 V. What is the capacitance? I know I have to use c=Q/V, but which charge do I use the positive or negative?

This one doesn't make sense to me. A lost person may signal by flashing a flashlight on and off using morse code. This is actually a modulated EM wave. Is it AM or FM? What is the frequencey of the carrier, approximately? How can a light wave be AM or FM? I don't get it. I thought...

First here is the question: Who will hear the voice of a singer first? A person in the balcony 50m away from the stage, or a person 3000km away at home whose ear is next to the radio? How much sooner? Assume the mic is a few cm from the singer and the temperature is 20 degrees celcius...

Please assist me with this The work done to move a 1.0 C charge from point P to Q is 3.0 * 10^-4J. If the charge starts from rest and has 1.0 * 10^-4J of kinetic energy when it reaches point Q, what must the potential difference be between P and Q? For this would I use Work done =...

This question is giving me some difficulty. Under normal atmospheric conditions, the potential in the atmosphere near the Earth's surface rises 80 V for every metre of increased elevation. A) What direction will free electrons in the atmosphere move? B) Calculate the loss in electric...

but how do I find the magnitude of the electric charge on earth? I don't have enought information

I am having trouble doing this question. Measurements indicate there is an electric field surrounding the earth. Its magnitude is about 100 N/C at the Earth's surface and points to the centre of the earth. What is the magnitude of the electric charge on the earth? Is it positive or...

I do not know how to do the second part of this question. I never learned this. A laser used to weld detached retinas puts out pulses of 640 nm light, 25 ms long, which average 0.50 W output during a pulse. i) how much energy can be deposited pre pulse? ii) If the energy of a light...

hgfdkl; I still can get it totally. here is where I get to: GM/r1^2 + r1h = g I can't get rid of the r1h.

I was asked by someone, "Why do diamonds appear brilliant to the eye?" I am having trouble coming up with a solid answer. All I could find out was it has a high index of refraction of about 2.42. I need some assistance with this.

Here is the question: Violet light has a frequency of 7.5 * 10^14 hz and travels from air to glass at an angle of 30 degrees. The index of refraction for violet light is 1.54. A) Find the angle of refraction B) Find the wavelength in air C) Find the wavelength in glass D) What is the...