Spacetime diagram problem (spacelike intervals)

[Moataz]

Homework Statement

Suppose on a spacetime diagram, an event happens at x=-4, t=5 and another event happens at x=0 and t=6. If there is a frame such that the two events happen simultaneously, what would the relative speed of that frame be?

Homework Equations

The Attempt at a Solution

I know this interval is spacelike ( between the two events) but the answer says Relative speed=Beta=Delta(t)/Delta(x)=0.25 But I do not understand why is the speed=time over distance here?

 

[M. Splinter]

In a spacetime diagram, a point is an event. If a line connects two points, or two events, the line is called the line of simultaneity. The slope of the line of simultaneity is the inverse of the slope of the world line of a moving frame. Therefore, you can find the slope of the line of simultaneity from the two point you are given and then find the slope of the world line.

 

[Chestermiller]

Homework Statement

Suppose on a spacetime diagram, an event happens at x=-4, t=5 and another event happens at x=0 and t=6. If there is a frame such that the two events happen simultaneously, what would the relative speed of that frame be?

Homework Equations

The Attempt at a Solution

I know this interval is spacelike ( between the two events) but the answer says Relative speed=Beta=Delta(t)/Delta(x)=0.25 But I do not understand why is the speed=time over distance here?

I agree with you. The relative speed should be 4.

Chet