00:01
Okay, so in order to figure out the answer for this question, we can come out with such an equation, which is vba is equal to vla plus vbl over 1 plus vl xx2a times vbl over c squared.
00:13
And vba is the one we are looking for to determine.
00:16
And bla is the speed of lab that is relative to the electron a, and vbl is the speed of electron b that is relative to the lab, okay? c is just the speed of light.
00:28
Since we know val is equal to 3 over 5c and vbl is 4 over 5c.
00:33
Therefore vla is equal to negative 3 over 5c, okay? because we need to consider electron a is at rest.
00:41
And therefore, the electron b will still have the speed that is relative to the left and point toward west, okay? now the laboratory should have a speed that is relative to the a and is point over the east.
00:58
Okay, because you found a question, we at the beginning we were considering the laboratory was a fixed point...