00:01
In this problem, we have two rocket ships, a and b.
00:06
And rocket ship a fires a missile at 0 .63c toward b.
00:17
This is in the perspective of rocket ship a.
00:20
Everybody else is moving.
00:22
He's at rest.
00:23
His frame of reference, that's attached to him.
00:26
There's no motion relative to his own frame.
00:29
Now, let's look at this from the perspective of b's frame.
00:33
So he's now at rest.
00:39
V miso relative to b is given as 0 .945 c.
00:46
Well, we're treating obviously the positive direction is to the right, negative direction to the left.
00:52
And in the end, we're going to get the relative velocity between a and b.
00:59
And i'll talk more about that in a few minutes.
01:03
So you would have v ab which is minus v ba if a says b's moving away from him and say a speed of 0 .7 b will say that a say moving away from to the right so a says b's moving away from him to the right at a speed of 0 .7 c b from b's perspective they got to be partying company that means he'll say that a is moving to the left with speed 0 .7 c.
01:39
So that's where the minus sign comes in, just to change the direction, but the speed's the same.
01:43
Speed's the same.
01:45
So this is relative to b's frame.
01:47
This is relative to a's frame.
01:50
And we have all our information...