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Planck's Constant

Posted: Sun Oct 15, 2017 8:50 pm
by Husnia Safi - 1K
When would I need to use Planck's constant?

Re: Planck's Constant

Posted: Sun Oct 15, 2017 9:00 pm
by Andrea Grigsby 1I
whenever you need to use an equation with the constant "h" in it.
eg E=hv

good thing is, the value is on the formula sheet so we don't have to memorize it :)

Re: Planck's Constant

Posted: Sun Oct 15, 2017 9:11 pm
by Ruohan Sun 3I
when using the equations E=hν and λ=h/p

Re: Planck's Constant

Posted: Sun Oct 15, 2017 9:16 pm
by Gurpreet Khamba 1J
It can also be used to find E (Energy) when the frequency is not known. To do this, you would use the relation v has with c (speed of light) and λ (wavelength).
This results in the equation: E = (hv)/λ
The constant is also used in the uncertainty principle.

Max Planck received a Nobel Prize in 1981 "in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta".

Re: Planck's Constant

Posted: Sun Oct 15, 2017 11:58 pm
by Michelle Lu 1F
Plank's constant is used in a variety of common equations such as E = (hv)/λ and λ=h/p and it was a constant that was found experimentally.

Re: Planck's Constant

Posted: Mon Oct 16, 2017 11:12 pm
by Susie Lee 2I
Whenever you see "h" in a formula! Don't get it confused with "p"!!

Re: Planck's Constant

Posted: Tue Oct 17, 2017 2:45 pm
by Adrian Lim 1G
Planck's constant is a set number for the constant h. It is used in formulas, such as E = hv. It will be given to you on the formula sheet. Just to reiterate the above reply, don't get it confused with p. p stands for momentum and is equal to the mass * velocity.

Re: Planck's Constant

Posted: Tue Oct 17, 2017 8:59 pm
by Josh Moy 1H
Use planck's constant whenever you need to use/derive equations involving the variable h

Re: Planck's Constant

Posted: Fri Oct 20, 2017 1:57 am
by Jasmin Tran 1J
Also, make sure the variable is h and not "h bar" (the h with a cross on the top), because h bar refers to the uncertainty principle and has a different value than h, which is Planck's constant.

Re: Planck's Constant

Posted: Sat Oct 21, 2017 12:39 am
by Patricia Macalalag 2E
Don't forget that the units for Planck's Constant are joules times seconds!

Re: Planck's Constant

Posted: Sun Oct 22, 2017 6:52 pm
by Christy Zhao 1H
You also use Planck's constant in the equation relating the kinetic energy of an ejected e- to the energy of an incident photon.