Minkowski diagram, where to put an event

[Redwaves]

Homework Statement

At t=0 A is moving
At t = -1/3 ms B is at 300km north and send a light beam
Draw the Minkowski diagram then tell if the light beam will reach A

Relevant Equations

##-\frac{1}{3} ms = -\frac{10^{-3}}{3}s##
##300km = 3\cdot10^5 m##
##ct = -\frac{10^{-3}}{3}s \cdot c##

I drew the Minkowski diagram, but I'm not sure if this is correct.
From what I drew the angle between x and ct ##\approx 0##
then the event is "inside" the light ray and will eventually reach A.

 

[Chestermiller]

Is there any relative velocity between A and B, and if so, how much?

 

[Redwaves]

Is there any relative velocity between A and B, and if so, how much?

No, that's all I have

 

[Chestermiller]

No, that's all I have

Well, it seems like there is something missing from the problem statement. What is the exact wording?

 

[Redwaves]

Well, it seems like there is something missing from the problem statement. What is the exact wording?

The statement is in french, here is the google translate.

A and B are two cars At t = 0, car A starts to move forward. B sent a light signal to try
to warn him: B is 300 km to the North and sends his signal at t = - (1/3) ms;

I have to draw the world line of that light signal
I'm wondering if I should have draw the cone of light instead of the diagram above?

Thus, since opposite/adjacent < 1, the event in inside the cone of light and if the event in inside the cone of light, the light signal will eventually reach A. Is it correct?

Edit: Since ##ct = 300000000 \cdot -\frac{10^{-3}}{3} = 100000m##
And ##100000/300000 < 1## this is not inside the cone of light, so it will not reach A.

 

[Chestermiller]

The statement is in french, here is the google translate.

A and B are two cars At t = 0, car A starts to move forward. B sent a light signal to try
to warn him: B is 300 km to the North and sends his signal at t = - (1/3) ms;

I have to draw the world line of that light signal
I'm wondering if I should have draw the cone of light instead of the diagram above?

Thus, since opposite/adjacent < 1, the event in inside the cone of light and if the event in inside the cone of light, the light signal will eventually reach A. Is it correct?

Edit: Since ##ct = 300000000 \cdot -\frac{10^{-3}}{3} = 100000m##
And ##100000/300000 < 1## this is not inside the cone of light, so it will not reach A.

Any information on the speed with which car A starts to move forward?

 

[Redwaves]

Any information on the speed with which car A starts to move forward?

That's all I have.