What is the mass of a proton traveling at a speed of 1.8 108 m / s? The rest mass of the proton is considered equal to 1 amu.

The mass of a body flying with a speed close to the speed of light is determined by the formula:

m = m0 / √ (1 – v ^ 2 / c ^ 2), m0 is the rest mass, c is the speed of light, v is the speed of the body.

We substitute in the above formula the values from the condition:

m = 1 / √ (1 – (1.8 * 10 ^ (8) ^ 2 / (3 * 10 ^ 8) ^ 2 = 1 / √ (1 – 0.36) = 10/8 = 1.25.

Answer: the required proton mass is 1.25 amu.