Calculating Time and Distance in Lorentz Transforms: A Homework Example

  • Thread starter Thread starter mattst88
  • Start date Start date
  • Tags Tags
    Lorentz
mattst88
Messages
28
Reaction score
0

Homework Statement



At x = x' = 0 and t = t' = 0, a clock ticks on a fast spaceship (gamma = 100). The captain of the ship heads it tick again 1.0 s later. Where and when do we (the stationary observers) measure the second tick to occur?

Homework Equations



t = \frac{t'}{\gamma}
x' = \gamma(x - vt)
\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}

The Attempt at a Solution



First, I solve for velocity.
v = c\sqrt{1 - \frac{1}{100}^2} = 0.9995c

Next, solve for t when t' = 1.
t = \frac{t'}{\gamma} = \frac{1}{100} sec

Finally, solve for x'.
x' = \gamma(x - vt) = 100(0 - (0.9995c)(\frac{1}{100})) = 0.9995c

Have I answered this correctly? Thanks.
 
Physics news on Phys.org
The spaceship is defined as the moving object, so proper time is measured on the Earth. Time appears to be going slower for the spaceship. So we could write that:

t_{earth} = \gamma t_{spaceship}

Sam :smile:
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top