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This is the q. I'm pretty sure that they've got it wrong.

Two cars A and B pass each other at a speed of 0.18c. A person in car B says her car is 6.00m long and car A is 6.15m long. What does a person in car A measure for these two lengths?

Obviously, the person in car A would measure her car to be >6.15m long and car B to be <6.00m.

Because they pass each each at relativistic speeds, it would be prudent to use loretz transformations to find their relative speeds (even though galilean transformations would probably suffice).

speed relative to one another = (.18+.18)/(1+(.18*.18/1)) = (.18+.18)/1.0324 = .3487c (will use exact value though)

Thus, the length of car B is 6*1/loretz factor = 5.62m

and the lengh of car A is 6.15*loretz factor = 6.56m

the answers they get are 6.25m for car A and 5.90m for car B.

Am i right?

Thanks.

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# Homework Help: Loretz transformations

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