00:01
Okay, so for question a, we can use the such equation here, which is l equal to l0 divided by gamma.
00:11
Okay? we know gamma, which the laurence factor is equal to 1 over square root, 1 minus v.
00:20
C squared.
00:21
Okay.
00:22
And l0 here is the distance that was matter from earth, okay? l here is the distance that was measured by the astronauts from the spaceship.
00:35
So therefore, in order to determine the distance, there will be measured from astronauts ' perspective.
00:41
We need to just simply use l equal to pre -plugging this equation here back into the o equation here.
00:50
We have square root 1 minus v square over c square and n times l0.
01:02
L0 in this case is the distance that was measured from earth observer, which is 30 light years.
01:15
And v, which is the speed of a spaceship, was given as 0 .a00c.
01:25
So therefore we can plug in to the equations.
01:28
Then we'll have l is equal to square root 1 minus 0 .a00.
01:39
And then c and then holding square over c square and times l i'm sorry 10 30 layers and this will give us square root 1 minus 0 .8 0 0 0 square square okay times 30 layers which is 0 .6 times 30 layers and it will give us the distance that will be measured from astronauts perspective is about 18 years.
02:35
Okay...