00:01
Okay, so this is the graph i drew based on the questions.
00:04
So 0 is us, okay? and s is the spaceship that was passing along the same direction with us, and we measure that the speed of the spaceship is 0 .50c.
00:15
And we also noticed that earth was moving away from us with the speed of 0 .90c.
00:19
So if i consider our direction is the positive direction.
00:23
That means the spaceship that was just passed by us who have a positive speed.
00:27
Oh, i'm sorry, the positive velocity, which is a positive 0 .50c.
00:30
And earth will have a negative velocity since it was moving away from us, okay, which is negative 0 .90c.
00:39
So the question was asking us to determine vsc, which is the velocity or the speed from the spaceship that was just passed by us from earth's observer.
00:53
Okay? so we have such equation here, which is vse, is equal to vso plus.
01:05
B -o -e and then plus amson -o -plus over 1 plus vso times v -o -e over c -square...