individual piece of the light beam contains the same amount of energy
17:03 and this release is the same amount of energy as every other pieces like
17:06 preceding and succeeding it
17:08 so unlike is just a stream of particles it follows that monochromatic light
17:13 having a narrow range of frequencies and thus a narrow range have energies
17:17 should yield the constant energy output which is exactly what we observed
17:22 finally the way picture light predicts that there should be a build-up
17:26 energy prior to their being a photo electric effect due to the existence of
17:30 the work function
17:31 the work function was empirically determined value varies with the type
17:35 that material being considered
17:37 is the amount of energy needed by an electromagnetic wave to free an electron
17:41 from a metallic surface
17:42 basically it's the threshold energy according to the weight picture applied
17:47 if a lightweight has low enough intensity the energy
17:51 incoming light beam should gradually build up energy until the energy of the
17:55 light overcomes the work function
17:56 at which point the photo electric effect may occur it we observed that the photo
18:01 electric effect took place immediately
18:03 there was no need for a build up a way better G because
18:06 once again individual pieces apply either we're capable of knocking out
18:10 electrons
18:11 or were and and this capability was determined immediately
18:15 you can have a beamer red light shining from a spotlight
18:18 and it will never release a single electron from a metal
18:21 no matter how long you shine it on there then you can have a beam a Buy Lead
18:25 light shining out a little laser pointer
18:28 and the Middle will immediately start shooting out electrons
18:31 from all this information I'm stunned found that the maximum kinetic energy
18:35 each photo electron
18:37 k max because H F minus p
18:40 where k max is the maximum energy open outgoing photoelectron
18:44 H is Planck's constant F is the frequency of the light beam
18:48 and he is the work function which again depends on the material being eliminated
18:53 now think again about what's happening during the photo electric effect
18:57 light which has a certain amount of energy is hitting electron that has zero
19:02 kinetic energy
19:03 since the electron a stationary if the transfers all its energy into the
19:07 electron
19:08 in the kinetic energy of the outgoing photo electron is equal to the lights
19:12 energy
19:12 minus whatever energy was needed to free the electron
19:15 and this is exactly what the equation is saying this term is the kinetic energy
19:20 of the outgoing photoelectron
19:22 and this term is the energy needed to free it so this term must be equal to
19:26 the energy that the incoming light contained
19:28 says the experiments seem to indicate that individual packets a flight were
19:33 responsible for the photo electric effect
19:35 as opposed to entire beams of light waves this expression refers to the
19:39 energy other single particle of light
19:41 a quantum a blight a photon
19:45 the energy of a photon is Planck's constant
19:48 times the photons frequency this formula
19:52 is called the plank I'm stein relation it was on sons analysis to the photo
19:57 electric effect
19:58 th