Mass of a particle at speed of light

[ally1h]

Homework Statement

I remember hearing in class that the mass of a particle nears infinity as the speed of the particle nears the speed of light. Is this true? And why is this true?

Homework Equations

The Attempt at a Solution

 

[LowlyPion]

Never let it be said the government isn't of some use.

From the US Energy Department:
http://www.Newton.dep.anl.gov/askasci/phy99/phy99186.htm

 

[ally1h]

Thank you! :)