Intensity Definition and 966 Threads

This is the SI unit for luminous intensity. The definition relates to blackbody radiation emitted at a certain temperature for a certain material (so I guess it ISN'T blackbody!), platinum, I think. Except... I don't understand the necessity for the introduction of this unit. Isn't...

Could someone explain to me the mathematical differences between impulse, intensity, and inertia? I mean, they all start with I's, but I still cannot determine any mathematical precision instead variation among these three.

Hello everyone! I'm having a real tough time with this one, maybe I can get a little help. A small helium neon laser emits red visible light with a power of 3.2 mW in a beam that has a diameter of 2.5mm. What is the intensity of the laser beam? Does this intensity obey the inverse square...

sound intensity level can be measured in dB & dB (A). What is the difference between the 2 scales?

Hello guys! I just need a tip. I wish to derive the intensity for a three-slit grating, and got stuck pretty close to the right answer. I've got a snapshot of my work at www.mypost.kit.net THANKS!

I have no idea what I'm doing wrong on this one. I'm having problems somewhere in the log conversions to W/m^2 I believe. A siren mounted on the top of towers produces a noise of 120 dB at a distance of 2 meters. Treating the siren as a point particle (and ignoreing reflection and...

Hi, i was interested in a detector that could measure the intensity of a radio wave of a particular frequency, at a point. Either by using a capacitor or a radio diode (or any other way). If such a devise exists please tell me where I can find one, if not any advise on how I might be able to...

The upper limit of the intensity level of sound waves is about 194 dB. This intensity corresponds to 100% modulation of the air; that is, the amplitude of the pressure oscillations corresponds to that of atmospheric pressure. What intensity (W/m^2) would be required to generate this level of...

If 2 flutist play their instruments together at the same intensity, is the sound twice as loud as that either flutist playing alone at that intensity? Why or why not?

I have a few pretty simple questions that I can't seem to find a clear answer to on the net... The energy of a light wave is directly proportionate to frequency and inversely proportionate to wavelength. This is due to the energy of a Photon being equal to hf. "f" is a constant, so the...

The problem states: A microphone in the ocean is sensitive to sounds emitted by popoises. To produce a usable signal , sound waves striking the microphone must have an intesity of 10.6 dB. If porpoises emit sound waves with a power of 0.0502 W, how far can a porpoise be from the microphone and...

having problems trying to understand and derive the equation for intensity in the double-slit interference pattern. any sort of help would be welcomed. thanks

Quick Physics Help... X and Z represent point charges of -2.4 x 10^-3 C and +3.3 x 10^-2 C respectively. Calculate the magnitude and direction of the electric field intensity at point Y, 5.00 cm from X and 8.50 cm from Z (they all live in a line). Can sumone help me?

How would you calculate the intensity using relative amplitude. Say for a violin...how would you calculate it's intensity for one of it's harmonics or overtones.

Hello Forum members I need help on a homework problem that I am unable to solve. the problem is as follows Given the radius of a star of 9.0 * 10^3 m and surface temperature of 10000 k (blackbody)find the intensity of radiation (watts/m^2) incident on a planet that is located 2.4 * 10^11...

A Radioactive source produces an intensity of radiation of 6000 Bq/M^2 at a distance of 5 meters from a source. Determine the intensity of the radiation at a distance of a)10 metres * Well i think it will be 3000 Bq/m^2 since it is further distance and is halved, can someone verify? b)...