00:01
In this problem, we're going to talk about length contraction.
00:03
So suppose that we have an object that has a proper length l, meaning that this is the length measured in the reference frame where this object is at rest.
00:14
And suppose that this object is moving with a certain speed v relative to an observer that's at rest relative to a reference frame s.
00:25
This observer measures the length of the object to be equal to the proper length.
00:30
Divided by gamma, where gamma is 1 over the square root of 1 minus v squared over c squared.
00:42
And in our problem, we have you and your friend, maria, and you both have spaceships that are identical.
00:56
You measure your own spaceship to be equal, to have a length of 100 meters.
01:03
So this is the proper length of your same.
01:05
Spaceships since they are identical, but you measure the length of your friend's spaceship to be equal to 90 meters.
01:17
In question a, we have to know what is the length that maria attributes, maria measures for your spaceship.
01:30
So notice that the maria spaceship is contracted due to the fact that she is moving relative to you.
01:39
So if this green box is your spaceship and this blue box is maria's spaceship, then she's moving with a certain speed v relative to you...