Need help with a question about momentum

  • Thread starter Thread starter stayfocused
  • Start date Start date
  • Tags Tags
    Momentum
Click For Summary

Homework Help Overview

The discussion revolves around determining the speed at which a proton must travel to match the momentum of a 6.0-MeV photon, focusing on the concept of momentum in the context of particle physics.

Discussion Character

  • Conceptual clarification, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the equation for momentum, P = E / c, and raise concerns about unit consistency when applying this equation. There are attempts to equate the momentum of the proton with that of the photon, leading to questions about the proper use of units.

Discussion Status

Some participants have pointed out the need for careful attention to unit systems, suggesting that mixing natural units with SI units can lead to confusion. There is acknowledgment of the issue regarding unit consistency, and one participant expresses gratitude for the clarification provided.

Contextual Notes

Participants are navigating the complexities of unit conversion between natural units and SI units, which is critical for solving the problem accurately. The original poster appears to have initially overlooked this aspect.

stayfocused
Messages
2
Reaction score
0

Homework Statement



How fast would a proton have to travel to have the same momentum as a 6.0-MeV photon

Homework Equations


P= E / C


The Attempt at a Solution


P= E / C
= 6.0-MeV / 3.00x108m/s
 
Physics news on Phys.org
stayfocused said:

Homework Statement



How fast would a proton have to travel to have the same momentum as a 6.0-MeV photon

Homework Equations


P= E / C


The Attempt at a Solution


P= E / C
= 6.0-MeV / 3.00x108m/s
Welcome to Physics Forums.

You need to be careful with your units here, your mixing natural units and S.I. units. You need to pick a system and stick to it.
 
stayfocused said:

Homework Statement



How fast would a proton have to travel to have the same momentum as a 6.0-MeV photon

Homework Equations


P= E / C


The Attempt at a Solution


P= E / C
= 6.0-MeV / 3.00x108m/s


What's the problem here? Have you even put in any thought to it?

Yes P = E/c but if you're going to use that you need to make sure your E and c are in SI - that is - m/s and J

Once you find that you can equate that with the momentum of a proton - mv. You can look up the mass of the proton, and solve for v
 
That was my problem, I hadn't realized that i had the different units. Thank you!
 

Similar threads

Kinetic Energy of Colliding Protons
  • · Replies 54 ·
2
Replies
54
Views
11K
Final momentum of box with reflective interior hit by ideal laser
  • · Replies 4 ·
Replies
4
Views
1K
Relativistic Energy and Velocity
  • · Replies 2 ·
Replies
2
Views
1K
Relativity -- Momentum and energy
  • · Replies 6 ·
Replies
6
Views
2K
Momentum: instantaneous or average?
  • · Replies 9 ·
Replies
9
Views
1K
Finding the momentum of a photon
  • · Replies 11 ·
Replies
11
Views
3K
Calculating Momentum in an Observer's Frame of Reference
  • · Replies 1 ·
Replies
1
Views
2K
How do you derive the units for momentum for photons
  • · Replies 4 ·
Replies
4
Views
2K
Compton Scattering and Recoil Velocity
  • · Replies 3 ·
Replies
3
Views
4K
Calculate velocity of the fastest neutron inside a 96Mo nucl
  • · Replies 5 ·
Replies
5
Views
2K