An astronaut traveling forward at 0.87c holds a meterstick in spear-like fashion. An observer at rest sees the spear's length as
A)0.5 m.
B)0.87 m.
C)1 m.
D)1.25 m.
E)1.5 m.

Question

Quizplus · Accepted Answer

Due to the effects of length contraction, an object moving at a significant fraction of the speed of light (in this case, 0.87c) will appear shorter in the direction of motion to a stationary observer. The length contraction can be calculated using the formula L = L0 * sqrt(1 - v^2/c^2), where L0 is the proper length (the length of the object in the rest frame of the object, which is 1 meter in this case), v is the velocity of the object, and c is the speed of light. Plugging in the values, the observed length L will be less than the proper length, which in this scenario results in the meterstick appearing to be 0.5 meters long to the stationary observer.

An Astronaut Traveling Forward at 0