Recoil speed of an atomic nucleus

AI Thread Summary
The discussion revolves around calculating the recoil speed of an atomic nucleus after it emits a gamma ray of 24.0 keV. The nucleus has a mass of 9.53e-26 kg, and the challenge lies in applying the correct physics principles to find the recoil speed. Initially, the poster struggled with the calculations, attempting to equate kinetic energy with rest energy and gamma ray energy without success. Guidance was provided to use conservation of momentum and the photon momentum formula to solve the problem. Ultimately, the correct recoil speed of the nucleus is determined to be 134 m/s.
Qnslaught
Messages
8
Reaction score
0

Homework Statement



An atomic nucleus is in an excited state. It decays to its ground state with the emission of a gamma ray having energy, Egamma = 24.0 keV. The nucleus has a mass of 9.53e-26 kg. What is the recoil speed of the nucleus? (Note: This may be an inelastic collision)

Homework Equations


1 eV = 1.6e-19 J

The Attempt at a Solution


I tried setting the final kinetic equal to the rest energy, and I tried setting it equal to the energy of the gamma ray, and I can't get the answer. The answer key lists the correct answer as 134 m/s, and I have no idea how to get to that.
 
Physics news on Phys.org
Why not use conservation of momentum?
Use the special formula for the momentum of a photon, using its energy to calculate its momentum.
 
Thank you, I got it now :)
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Energy of the photon emitted in a gamma ray decay
Replies
19
Views
3K
What is the energy of the alpha particle and recoiling nucleus?
Replies
9
Views
6K
Alpha Particle & Gold Nucleus Collision
Replies
17
Views
14K
Finding recoil velocity of an object during a collision
Replies
9
Views
2K
Potential difference of helium nucleus question
Replies
2
Views
8K
What is the orbital radius of a muon captured in the n=1 ground state of Carbon?
Replies
13
Views
2K
Electrons and their little role in nuclear physics
Replies
1
Views
2K
What is the correction to the wavelength of an emitted photon due to recoil?
Replies
4
Views
4K
Magnitude of the current flowing around the nucleus in the Bohr mode
Replies
3
Views
3K
Caesium 137 is an unstable isomer
Replies
13
Views
3K

Hot Threads

Recent Insights

Back
Top