In the cabin of a jetliner that cruises at 600km/h, a pillow from an overhead rack falls into your lap below since the jetliner is moving so fast, why doesn't the pillow slam into the rear of the compartment when it drops? What is the horizontal speed of the pillow relative to the

Question

In the cabin of a jetliner that cruises at 600km/h, a pillow from an overhead rack falls into your lap below since the jetliner is moving so fast, why doesn't the pillow slam into the rear of the compartment when it drops? What is the horizontal speed of the pillow relative to the 
ground? Relative to you inside the jetliner

DrBob222 · Accepted Answer

The jetliner is moving at 600 km/hr. You are moving at 600 km/hr. The pillow and everything else in the cabin is moving at 600 km/hr. The speed relative to the ground is 600 km/hr for the pillow. The speed of the pillow relative to your lap is zero (because both of you are moving at the same speed).