An electron with a speed of 0.988c is emitted by a supernova, where c is the speed of light. What is the magnitude of the momentum of this electron?

Thanks for any help you can offer! I've tried so many things!

3 answers

it's mv/√(1 - v^2/c^2)

see

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html
the momentum is the product (multiply) of the relativistic mass and the velocity

the relativistic mass is the rest mass multiplied by gamma (the relativistic "fudge factor")

gamma = 1 / sqrt[1 - (v² / c²)]

p = gamma * rest mass * v

hyperphysics (web) is a good reference
So this is how I calculated, but can speed be taken for the velocity?