Special Relativity (Transformation question) Check Answer.

AI Thread Summary
The discussion revolves around a physics homework problem involving the angle of a mast on a moving boat as observed by a stationary observer. The initial attempt utilized the Lorentz Transformation to derive the angle but was deemed incorrect. The correct approach emphasizes the need to account for length contraction, which is derived from the difference in x coordinates rather than just transforming individual coordinates. The length contraction formula indicates that the observed length is affected by the relative velocity between the observer and the moving object. Understanding these principles is crucial for accurately solving problems in special relativity.
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Homework Statement


A boat with mast at angle θ to its deck is traveling at velocity v relative to an observer, what angle does this observer see.

Homework Equations


The Attempt at a Solution


So by using Lorentz Transformation: x'=(x-vt)*g where g=gamma
The mast is length 'r'' and at an angle θ' to the deck of the moving boat, so x' = r'*cos(θ')
By substitution, r'*cos(θ') = (x-vt)g and θ' = cos-1(x-vt/r'*√(1-(v2/c2))).

Am I right or not? Thanks
 
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Ah, yes, this is a very good problem, but only if you do the follow up of looking at the problem using velocities (that is to say a spotlight mounted to a boat forming an angle).

Anyway, to get to your answer: no, sorry it's not right. You just transformed x coordinates, but length is the difference between x coordinates. The length contraction formula is actually derived through the difference in x coordinates L'=x2'-x1'=x2*g-vt*g-x1*g+vt*g=g*(x2-x1)=g*L.
 
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