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29 Mar 2008 23:07:21 IST

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H atom initially at rest emits a photon in transition n=5 to n=1 ,find its recoil speed

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H atom initially at rest emits a photon in transition n=5 to n=1 ,find its recoil speed

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pulkit tomar

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29 Mar 2008 23:08:46 IST

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H atom initially at rest emits a photon in transition n=5 to n=1 ,find its recoil speed

Akhil

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Joined: 17 Jan 2008

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30 Mar 2008 00:16:11 IST

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=R_H(1/n₁²-1/n₂²)
also

=h/p
now
p=h/

=hR_H(1/n₁²-1/n₂²)

conserving momentum
we have
m*v=hR_H(1/n₁²-1/n₂²)
where v is recoil velocity
m is mass of atom

m=1.6*10^-27
h=6.626*10^-34Rh=10976800
n1=4,n2=5

put in values
i am getting v=0.103 m/s

Krishna Gopal Singh

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Joined: 29 Dec 2006

Posts: 5153

30 Mar 2008 11:08:39 IST

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Perfect answer. If lamda is wavelength of photon then velocity of atom is h/(m*lamda)

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