Calculating Distance in Galilean Transformations

[aaku516]

Homework Statement

A bus travels forward at a constant speed of 24 m/s down a straight highway. the driver puts on her sunglasses, and 3.5 s later, a passanger stiing 5 m behind her drops a pen. In the frame of reference of the earth, what is the distance seprating these events?

Homework Equations

x = x' + vt
Δx = Δx' + vΔt
u = u' + v

a = a'

The Attempt at a Solution

Ahh Cannot understand this problem, the part of "relative to the earth" confuses me!

 

[CompuChip]

Suppose that we put a measuring tape inside the bus, with the x = 0 position below the driver seat. Then "relative to the bus", i.e. with respect to this tape, the first even happens at x = 0 and the other event happens at x = 5, right?

Now put a similar measuring tape on the street, exactly such that the driver passes over the x = 0 position as she puts on her sunglasses. At what position with respect to this coordinate system is the passenger that drops the pen 3.5 seconds later?