http://grephysics.net/ans/9277/94

If gamma = 5/4, then beta does not equal 3/4. How is C the answer? When gamma = 5/4, then beta should be 3/5, NOT 3/4. So I thought the answer was E... Has anyone run into this before? Maybe I'm an idiot, though

-Maxwell's Demon

## 9277 #94

- Unnatural Log
**Posts:**46**Joined:**Fri Aug 15, 2008 4:07 pm

### Re: 9277 #94

Remember that the gamma applies distributively in a Lorentz transform, like this:

x' = gamma(x - vt)

t' = gamma(t - vx/c^2)

So you're right that beta = 3/5, but the coeffcient of t (in x') and the coefficient of x (in t') is not beta, but rather beta multiplied by gamma, ie 3/5 x 5/4 = 3/4.

I think that's it.

x' = gamma(x - vt)

t' = gamma(t - vx/c^2)

So you're right that beta = 3/5, but the coeffcient of t (in x') and the coefficient of x (in t') is not beta, but rather beta multiplied by gamma, ie 3/5 x 5/4 = 3/4.

I think that's it.