Need help with a question about momentum

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SUMMARY

A proton must travel at a specific velocity to match the momentum of a 6.0-MeV photon. The momentum of the photon is calculated using the equation P = E / c, where E is the energy in joules and c is the speed of light (3.00 x 108 m/s). To find the proton's velocity, one must convert the energy from MeV to joules and then equate the photon momentum to the proton's momentum, represented as mv, where m is the mass of the proton. The key takeaway is the importance of consistent unit systems when performing calculations.

PREREQUISITES
  • Understanding of momentum and its formula (P = mv)
  • Knowledge of energy units, specifically MeV and joules
  • Familiarity with the speed of light (c = 3.00 x 108 m/s)
  • Basic understanding of particle physics, particularly protons
NEXT STEPS
  • Convert energy from MeV to joules for precise calculations
  • Learn about relativistic momentum for high-speed particles
  • Study the mass of a proton and its implications in momentum calculations
  • Explore unit conversion techniques in physics to avoid mixing systems
USEFUL FOR

Students studying physics, particularly those focusing on particle physics and momentum calculations, as well as educators seeking to clarify concepts related to energy and momentum in different unit systems.

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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
 
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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!
 

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