A rock is lauched from the moon and travels away from it at a speed of 2/5. Call the event of the rocket's lauching event A. After 125s as measured in the reference frame of the moon, the rocket explodes: call this event B. THe light from the explosion travels back to the moon: call this reception event C. Let the moon be located at x=0 in its own reference frame, and let event A define t=0. Assume that the rocket moves along the +x direction.
a) Draw a spacetime diagram of the situation, drawing and labeling the worldlines of the moon, the rocket, and the light flash emitted by the explosion and received on the moon.
b) Draw and label events A, B, and C as points at the appropiate places on the diagram. Write down the t and x coordinates of these events.