If you have a drawing of a square (labeled ABCD starting at lower left and going clockwise) and it is first at rest in an inertial frame. When this square moves, length contraction changes its shape. In each of the following three situations the speed is the same, and the velocity is in the plane of the square. when is the area of the object the least if the velocity is directed paralled to:(adsbygoogle = window.adsbygoogle || []).push({});

a) side AB

b) diagonal AC or

c) side AD.

In which of these situations is the area of the object the least?

I know that length contraction occurs only along the direction of the motion. Dimensions perpendicular to the motion are not contracted. That is why choice (a) has the larges area and is not the answer.

The answer is (b), but I don't understand why. Please expain.

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# Length contraction of a square

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