Mass in MeV/c2 of a particle with a mass of 4.032u

[jsmith613]

Homework Statement

A particle has a mass of 4.032u. What is its mass in MeV/c²

Homework Equations

The Attempt at a Solution

4.032u = 4.032 * 1.66*10^-27 = 6.69*10^-27 kg
Energy equivalent, E = mc²: = (6.69*10^-27)*(3*10⁸)² = 6.02 *10^-10J

J→eV (divide by 1.6∗10^-19) )=3.76∗10⁹ eV=3760 MeV

How do I find it for MeV/c²

 

[Spinnor]

1MeV/c^2 = 1e6*1.6e-19/9e16 kg = 1.7e-30 kg

so 1 = [1MeV/c^2]/1.7e-30 kg = 1.7e-30 kg/[1MeV/c^2]

multiply your answer, 6.69*10-27 kg, by the right factor above?

 

[vela]

Homework Statement

A particle has a mass of 4.032u. What is its mass in MeV/c²

Homework Equations

The Attempt at a Solution

4.032u = 4.032 * 1.66*10^-27 = 6.69*10^-27 kg
Energy equivalent, E = mc²: = (6.69*10^-27)*(3*10⁸)² = 6.02 *10^-10J

J→eV (divide by 1.6∗10^-19) )=3.76∗10⁹ eV=3760 MeV

How do I find it for MeV/c²

You tack on /c² to the answer you found: 3760 MeV/c².

 

[jsmith613]

You tack on /c² to the answer you found: 3760 MeV/c².

why is this true?

 

[vela]

E = mc² ⇒ m = E/c² = (3760 MeV)/c². You just don't actually plug in a value for c. Instead you make it part of the units.