## GR0877 Problem 94

**PROBLEM STATEMENT**: *This problem is still being typed*.

**SOLUTION**: (**C**) Lorentz transformation suggests that for the observer moving at constant speed parallel to -axis the event (flash of light) that occurs at for the observer is at time (we assume is moving in the positive direction of and at a zero time according to both observers the origins of their reference frames coincide, therefore is negative; this means that event (as observed by ) occurs seconds *before *the other). Let , then, using units in which , one has or (for such an approximation the calculation error will be 7%). The closest choice is (C). If you calculate the square root in the above equation fairly, you will get .

*Found a typo? Comment!*

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please define your variables! It makes it much more difficult to understand your entire set of solutions. there are more than one set of common variables to represent various physical properties and you generally use one of the less common ones.

is the only ‘uncommon’ variable in this particular solution and I clearly defined it.

Somewhat confused about this solution. Why is alpha = (c*t)/x_0? It from your original t’ equation that it should be (c^2*t)/x_0 = -gamma*v. What happened to the c squared term, and the negative sign? Also, how come you set c = 1 for alpha in the last step but not in the one just previous to it.

Can you use space-time interval to solve this problem? Like find the contracted length and solve for v ?

I somehow got 0.39c instead of 0.36.

Approximating \alpha as 2/5 makes the calculation at the end a bit easier.