Solving Equations for t': Negative Time Confusion

[Pochen Liu]

Homework Statement

How can the answer be negative time?

Relevant Equations

*attached

Equations:

Question:

Using the equation for t' I got the answer -0.00000499756s (Wrong anyway)
As we know the values:
v = 0.67c m/s
x = 3900 m
t = 0.000005 s

Also how can time be negative? Does this mean that event 2 happened before the first event when t = 0?

 

[PeroK]

Problem Statement: How can the answer be negative time?
Relevant Equations: *attached

Equations:
View attachment 243341

Question:
View attachment 243342

Using the equation for t' I got the answer -0.00000499756s
As we know the values:
v = 0.67c m/s
x = 3900 m
t = 0.000005 s

How can time be negative? Does this mean that event 2 happened before the first event when t = 0?

If events in one reference frame are spacelike separated (i.e. the distance between them is greater than the time between them multiplied by ##c##), then in another frame they may happen in a different order.

 

[Pochen Liu]

If events in one reference frame are spacelike (i.e. the distance between them is greater than the time between them multiplied by ##c##), then in another frame they may happen in a different order.

What am I doing wrong?
t' = (0.000005 - (0.67*3900)/c)/sqrt(1-0.67^2)
t' = -0.00000499756s

A hint would be amazing! Have I fundementally misinterpreted the equation

 

[PeroK]

What am I doing wrong?
t' = (0.000005 - (0.67*3900)/c)/sqrt(1-0.67^2)
t' = -0.00000499756s

A hint would be amazing! Have I fundementally misinterpreted the equation

I haven't checked the numbers but that looks correct.

 

[Pochen Liu]

I haven't checked the numbers but that looks correct.

Sorry I forgot to mention it's wrong

 

[PeroK]

Sorry I forgot to mention it's wrong

What is supposed to be the answer? I'm only on my phone, so hard to check properly.

 

[Pochen Liu]

They don't provide us answers sadly

 

[Orodruin]

If events in one reference frame are spacelike

Jus a pet peeve about terminology. The events in themselves are not spacelike (it is not clear what that would mean), their separation is.

 

[PeroK]

They don't provide us answers sadly

How do you know it's wrong?

Ps I get ##-0.5 \mu s## on my phone.