00:01
All right, so for part a, let's say we have a proton, and we're told the mass of the proton is 938 million electron volts per c squared.
00:11
And we want to compute the momentum if it's moving at a speed of 0 .801c.
00:16
So the momentum, there are a couple of ways of doing this.
00:21
One, you can use your energy momentum relationship that says like the total energy squared is equal to the rest mass energy.
00:31
Squared plus p squared c squared um but we could also probably simpler is just write the momentum is the larynx factor times the mass times the velocity so the lorins factor for this speed for any speed is one over the square root of one minus v squared over c squared for this particular value point 801 this should be about 1 .67 so our momentum is going to be 1 .67 times 9 .9 .7 times 9 38 m .e .v.
01:06
Per c squared times 0 .801c.
01:13
And so this should come out to, we're right as 1 .255 billion electron volts divided by the speed of light.
01:25
And, you know, this is, you know, 1 ,255 mev per c...