The Photoelectric Effect

[maddmattindahat]

Im laying in bed, quite late, thinking about how i have to walk in 15cm snow tomorrow, watching (and enjoying) this vid. Since my girlfriends away, i have nothing to do like go to the movies or just hang out with her. I need to get a life lmao!!!:D

[TheBlueastrosailor]

I sneezed at the same time as the person in the class, weird.

Also thanks that was very helpful

[joshuaB765]

Is this A level?

[edwinallston]

@baked4211 ur retarded...

[K1I2A2R9A3]

This helped more than the lectures I attended. THANK YOU! I have an exam in a day and a half.

[CydoniaKnight1]

Thanks a lot

Very good lesson

[jamie070194]

this guy is an excellent physics teacher. so clear and concise. well done

[naturalfeatures]

Fantastic video

[stan021]

forexample this effect is used by photoelectric cells widely used in industry.

[FlirtWithDanger07]

of couse now that i finished my physics course i can understand the photoelectric effect.

[XenomexTutorials]

If just my teacher for physics was like this guy...............

[Zobaire90]

@XenomexTutorials i personally believe that most physics teachers are the same but, its just that we pay extra attention here because we have no choice but to. if we payed the same amount of attention during class, we would of had the same conclusion for our teachers.

[audreykimmy]

wow! you are so lucky to have had a teacher like that (:

[whichwaywest]

awesome!

[Orion22deblanc]

would love to see what would happen if you placed a compass in the area of where the electrons should fly off to...

[scrapingskies]

this video was extremely helpful. thank you so much!

[haeresy]

this is basically how trees work...their roots grow 90 degrees to each other and the branches all grow at 45 - 52 Degrees, which in engineering creates magnetism. Bend a metal bar to 90 degrees and it will create a " - " force and bend a metal bar to 45-52 and it will create " + " force. The Earth creates "negative ions" and has a 300-400 times the amount of electrons " - " compared to the atmosphere "sunlight" which are protons " + ". The sugars "crystals" store this energy as electrolytes.

[ispyaspy]

magic?

[ollieoniel]

or does It demonstrates the skin effect?

[milnusthegnome]

God, I hate these types of Classes. They never ever work...

[Jewlzeh]

hehehe the accents are so cool :3

[29erguru]

extremely helpful, this guy is one of the few physics teachers who have communication skills on a par with their knowledge.....

[sashetoa]

Those electrons circulate like direct current?

[fightstar62]

This guy > my physics teacher

[QQninja92]

omg dude ur awesome. i was struggling in my physics class till i saw this xD

[nightvid08]

This is a serious misconception which has found its way into too many textbooks today. The basic features of the photoelectric effect DO NOT demand a description using "photons". In fact, a CLASSICAL electromagnetic field works as long as the electrons in metal are QUANTUM MECHANICAL (described by the Schrödinger equation). There have been many published papers on this issue, a good example being

Lamb, Willis E.; Scully, Marlan O. (1968). "The photoelectric effect without photons".

[1001014]

has this got anything to do with E=hf? h being the Planck's constant and f being freq. If f is too low i.e. (infrared and lower), the energy of photos are not enough to knock electrons off?

[zanfankid]

yes it does, basically, each metal has a minimum frequency that will cause the photoelectric effect, for example Cesim has a minimum frequency acceptance of 4.60x10^14 Hz.

so to calculate the lowest amount of energy a photon has to be carrying to cause cesium to release electrons you just use E=hv (v is "nu" used to describe freq,) or E=hc/wavelength if you only know the wavelength. The result will be the number is in Jules.

[UncleKennybobs]

@1001014 Yes it has but it's better you look up the details yourself rather than me trying to explain it over YouTube.

The electrons will only absorb photons of certain frequencies.

[1001014]

Phet University of Colorado.

[angryparrot]

This prof. is brilliant...

[Veracityred]

this is amazing classroom teaching. may there be more such teachers.

[im18onthis]

GO ON CUNNERS!!!!!!!!!!!

[jehushaphat]

anyone knows his name?

[snowboarderx004]

Bob Miller the 5th

[JD167]

Very helpful, thanks a lot

[addieroxrev09]

it's photoelectric effect that made me take up physics.. the entire concept is simply amazing. i love it. nice explanation

[downeyc3]

Keep up the good work - great job.

[EyYoMyDude]

really good job with the explanation

[theindfla]

I wish more teachers were able to teach like you.

[fishbobboi]

what is the website for the first part? please

[yerrahyouknow]

see thephysicstecherdotie and scroll down to the link for The Electron

[guyjos]

@fishbobboi Phet

They have loads of these

[fatima5556]

thanks

[xTriad]

Thanks, this is a very good video.

[kavoos1000]

perfekt , thank you a lot ..

[anilkrchaubey]

thanks for providing such useful views

[Dreamantigone]

I get it! Thanks so much

[mynamesjimmyg]

cool :) is this a uni lecture? or school lesson?

im wondering, wat is that instrument that the negatively charged metal was on? how does it work?

very interesting :)

[bigmike1250001]

its called a gold leaf electroscope and it shows if an object is charged, however not the sign of the charge. what he did there was place a negetively charged obect on the cap which repelled negetive charges to the bottom of the electroscope. as then both the metal prod and the gold leaf were negetively charged, they repelled themselves and the gold leaf stood up.

[ChaosxLord]

thanks, that was really helpful =]