Finding the magnitude of impulse

[oalanojr]

Homework Statement

A proton has mass 1.7×10−27 kg. What is the magnitude of the impulse required to increase its speed from 0.991c to 0.994c?

Homework Equations

Impulse = mV_f{}-mV_i{}

The Attempt at a Solution

Impulse = mV_f{}-mV_i{}
= 1.7e-27*(.994*3e8)-(1.7e-27*(.991*3e8))
= 5.0694e-19 -5.0541e-19
Impulse = 1.53e-21

I've triple checked my work and I still come up with the same wrong answer. Am I missing something here??

 

[rock.freak667]

You may need to use the Lorentz transformation since the velocities are near c.

\gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}}

You may need to check over that formula for me since I may have typed it in incorrectly.

 

[oalanojr]

oh i totally forgot about gamma portion of the equation! Thanks for the help!