Two observers standing upright on their feet,move horizontally past each other and look at each other.The acceleration of both is zero and their relative speed is 0.500 c.Observer one looks at observer two and sees that she looks thinner than she is when she isn't moving.What does observer two see?
A)Observer one looks wider than she is when she isn't moving.
B)Observer one looks thinner than she is when she isn't moving.
C)Observer one looks the same as when she isn't moving.
D)Observer one looks like a vertical line with no width.

Question

Quizplus · Accepted Answer

This phenomenon is known as the relativistic length contraction, where the length of an object appears shorter when it is moving relative to the observer. As observer one is moving relative to observer two, she appears thinner to observer one. Similarly, observer two would also see observer one as thinner than she is when she isn't moving.

Two Observers Standing Upright on Their Feet,move Horizontally Past Each