Suppose a person is in a jet airliner traveling at a constant speed of 400 km/h in a constant direction. All windows are blocked, so they cannot see outside, and there are no vibrations from the engines. What experiment can be done to determine that they are in fact moving?
A) Suspend a ball by a thread from the ceiling and measure the angle the thread makes with the vertical.
B) None-all experiments will give the same results that one would get when at rest on the ground.
C) Measure the speed of a sound wave traveling up the aisle (toward the nose of the aircraft) and another traveling down toward the tail, and calculate the difference between the two results.
D) Drop a small rock and measure the distance it moves backward down the aisle as it falls.

Question

Quizplus · Accepted Answer

Given the conditions described (constant velocity, no external reference points, and no vibrations), all experiments conducted inside the jet airliner would yield results indistinguishable from those obtained if the plane were at rest. This is because, according to the principle of relativity, the laws of physics are the same in all inertial frames of reference, which includes both a stationary environment and one moving at constant velocity in a straight line.

Suppose a Person Is in a Jet Airliner Traveling at a Constant