Question

A certain particle is at rest with respect to you. Assuming that you measure its mass to be 1 g, what is its energy? 1 eV = 1.6 x 10^-19 J. Answer in units of MeV.

Answer 1

5.625×10²⁶ MeV

Step-by-step explanation:

m = Mass of particle = 1 g = 0.001 kg

c = Speed of light = 3×10⁸ m/s

Einstein's equation

E = mc²

⇒E = 0.001×(3×10⁸)²

⇒E = 9×10¹³ J

1 eV = 1.6×10⁻¹⁹ J

`\\\Rightarrow 1\ J=(1)/(1.6* 10^(-19))`

So,

`9* 10^(13)\ J=(9* 10^(13))/(1.6* 10^(-19))=5.625* 10^(32)\ eV`

Converting to MeV

1 MeV = 10⁶ eV

So,

`5.625* 10^(32)\ eV =5.625* 10^(26)`

The energy of the particle is 5.625×10²⁶ MeV.