Proper Length

1. Apr 12, 2007

ND3G

"proper" Length

What speed would the spaceship have to travel for its relative length to be half its “proper” length

Given:
Lo = 67m
L = 33.5

Required:
v

Analysis:
L = (Lo)(sqr(1-(v^2)/(c^2)))

Now, I calculate v = sqr((1-(L/Lo)^2)(c^2)) however that gives me an non-real anwer. Clearly my algebra is lacking somewhere.

Can anyone help me form a proper equation for this?

2. Apr 12, 2007

Dick

Your algebra looks fine. Your arithmetic seems to be lacking. L/Lo=1/2, 1-(1/2)^2=3/4 etc etc.

3. Apr 12, 2007

ND3G

Ah, yes, I was dividing Lo/L on paper. It is always the simplest things...

Thanks