Modern Physics

Relativistic Momentum

Equation of momentum determined in Classical Mechanics

In Classical Mechanics, a body of mass m and speed v has momentum p defined by the equation shown in the table above. This definition is suitable when the modulus of v is small compared to the speed of light. However, when the velocities are “high”, in order to maintain the Principle of Conservation of Momentum, it is verified that p must be given by:

In the above equation, m 0 is known as the rest mass. If we do:

The moment equation can be represented as follows:

In order for equation III to be equal to equation I , we can define the relativistic mass m by:

Thus, the equation    represents momentum in any case, as long as m takes the value of relativistic mass. Note that if v has a much smaller value than c, we have:

In equation II, we see that as the velocity approaches c , the denominator of the fraction approaches zero and the momentum becomes infinitely large.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Check Also
Back to top button