Answer:
Given:
Thermal Kinetic Energy of an electron, ![KE_{t} = \frac{3}{2}k_{b}T](https://tex.z-dn.net/?f=KE_%7Bt%7D%20%3D%20%5Cfrac%7B3%7D%7B2%7Dk_%7Bb%7DT)
= Boltzmann's constant
Temperature, T = 1800 K
Solution:
Now, to calculate the de-Broglie wavelength of the electron,
:
![\lambda_{e} = \frac{h}{p_{e}}](https://tex.z-dn.net/?f=%5Clambda_%7Be%7D%20%3D%20%5Cfrac%7Bh%7D%7Bp_%7Be%7D%7D)
(1)
where
h = Planck's constant = ![6.626\times 10^{- 34}m^{2}kg/s](https://tex.z-dn.net/?f=6.626%5Ctimes%2010%5E%7B-%2034%7Dm%5E%7B2%7Dkg%2Fs)
= momentum of an electron
= velocity of an electron
= mass of electon
Now,
Kinetic energy of an electron = thermal kinetic energy
![\frac{1}{2}m_{e}v_{e}^{2} = \frac{3}{2}k_{b}T](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7Dm_%7Be%7Dv_%7Be%7D%5E%7B2%7D%20%3D%20%5Cfrac%7B3%7D%7B2%7Dk_%7Bb%7DT)
![}v_{e} = \sqrt{2\frac{\frac{3}{2}k_{b}T}{m_{e}}}](https://tex.z-dn.net/?f=%7Dv_%7Be%7D%20%3D%20%5Csqrt%7B2%5Cfrac%7B%5Cfrac%7B3%7D%7B2%7Dk_%7Bb%7DT%7D%7Bm_%7Be%7D%7D%7D)
![}v_{e} = \sqrt{\frac{3\times 1.38\times 10^{- 23}\times 1800}{9.1\times 10_{- 31}}}](https://tex.z-dn.net/?f=%7Dv_%7Be%7D%20%3D%20%5Csqrt%7B%5Cfrac%7B3%5Ctimes%201.38%5Ctimes%2010%5E%7B-%2023%7D%5Ctimes%201800%7D%7B9.1%5Ctimes%2010_%7B-%2031%7D%7D%7D)
(2)
Using eqn (2) in (1):
![\lambda_{e} = \frac{6.626\times 10^{- 34}}{9.1\times 10_{- 31}\times 2.86\times 10^{5}} = 2.55 nm](https://tex.z-dn.net/?f=%5Clambda_%7Be%7D%20%3D%20%5Cfrac%7B6.626%5Ctimes%2010%5E%7B-%2034%7D%7D%7B9.1%5Ctimes%2010_%7B-%2031%7D%5Ctimes%202.86%5Ctimes%2010%5E%7B5%7D%7D%20%3D%202.55%20nm)
Now, to calculate the de-Broglie wavelength of proton,
:
![\lambda_{p} = \frac{h}{p_{p}}](https://tex.z-dn.net/?f=%5Clambda_%7Bp%7D%20%3D%20%5Cfrac%7Bh%7D%7Bp_%7Bp%7D%7D)
(3)
where
= mass of proton
= velocity of an proton
Now,
Kinetic energy of a proton = thermal kinetic energy
![\frac{1}{2}m_{p}v_{p}^{2} = \frac{3}{2}k_{b}T](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7Dm_%7Bp%7Dv_%7Bp%7D%5E%7B2%7D%20%3D%20%5Cfrac%7B3%7D%7B2%7Dk_%7Bb%7DT)
![}v_{p} = \sqrt{2\frac{\frac{3}{2}k_{b}T}{m_{p}}}](https://tex.z-dn.net/?f=%7Dv_%7Bp%7D%20%3D%20%5Csqrt%7B2%5Cfrac%7B%5Cfrac%7B3%7D%7B2%7Dk_%7Bb%7DT%7D%7Bm_%7Bp%7D%7D%7D)
![}v_{p} = \sqrt{\frac{3\times 1.38\times 10^{- 23}\times 1800}{1.6726\times 10_{- 27}}}](https://tex.z-dn.net/?f=%7Dv_%7Bp%7D%20%3D%20%5Csqrt%7B%5Cfrac%7B3%5Ctimes%201.38%5Ctimes%2010%5E%7B-%2023%7D%5Ctimes%201800%7D%7B1.6726%5Ctimes%2010_%7B-%2027%7D%7D%7D)
(4)
Using eqn (4) in (3):
![\lambda_{p} = \frac{6.626\times 10^{- 34}}{1.6726\times 10_{- 27}\times 6.674\times 10^{3}} = 5.94\times 10^{- 11} m = 0.0594 nm](https://tex.z-dn.net/?f=%5Clambda_%7Bp%7D%20%3D%20%5Cfrac%7B6.626%5Ctimes%2010%5E%7B-%2034%7D%7D%7B1.6726%5Ctimes%2010_%7B-%2027%7D%5Ctimes%206.674%5Ctimes%2010%5E%7B3%7D%7D%20%3D%205.94%5Ctimes%2010%5E%7B-%2011%7D%20m%20%3D%200.0594%20nm)
I don’t even know I’m so dumb.
IV - Temperature
DV - Light intensity
That's ONLY true when the pendulum is hanging
in the center position and not moving.
Answer:
a.
W
Explanation:
= temperature of the surface of sun = 5800 K
= Radius of the Sun = 7 x 10⁸ m
= Surface area of the Sun
Surface area of the sun is given as
![A = 4\pi r^{2} \\A = 4(3.14) (7\times10^{8})^{2}\\A = 6.2\times10^{18} m^{2}](https://tex.z-dn.net/?f=A%20%3D%204%5Cpi%20r%5E%7B2%7D%20%5C%5CA%20%3D%204%283.14%29%20%287%5Ctimes10%5E%7B8%7D%29%5E%7B2%7D%5C%5CA%20%3D%206.2%5Ctimes10%5E%7B18%7D%20m%5E%7B2%7D)
= Emissivity = 1
= Stefan's constant = 5.67 x 10⁻⁸ Wm⁻²K⁻⁴
Using Stefan's law, Power output of the sun is given as
![P = \sigma e AT^{4} \\P = (5.67\times10^{-8}) (1) (6.2\times10^{18}) (5800)^{4}\\P = 3.95\times10^{26} W](https://tex.z-dn.net/?f=P%20%3D%20%5Csigma%20e%20AT%5E%7B4%7D%20%5C%5CP%20%3D%20%285.67%5Ctimes10%5E%7B-8%7D%29%20%281%29%20%286.2%5Ctimes10%5E%7B18%7D%29%20%285800%29%5E%7B4%7D%5C%5CP%20%3D%203.95%5Ctimes10%5E%7B26%7D%20W)