What would happen? Would the water hit the roof of the elevator since the elevator is falling rapidly?
I thought about it when I put Eye Drops in an elevator.
In: Physics
The water will fall on the floor.
The two questions that are important here is ‘how fast does water fall?’ and ‘how fast do elevators move?’
A droplet of water has a terminal velocity of around 10 meters per second – the terminal velocity being the fastest it will fall under the force of gravity.
An average elevator may travel at a speed of around 1m/s.
What this means is that if you hold your bottle a meter above the floor, and pour out some water, it will take about 1/10th of a second for it to fall and hit the floor. During this 1/10th of a second however, the elevator will have continued descending, around 0.1m which the water will have to fall.
So it will take longer for the water to hit the ground of an elevator if you pour it out while descending (and conversely, less time if the elevator is rising), but only a tiny fraction of a second (about 1/100th second longer).
If you want your water to float, you would need the elevator to be moving at a speed equal to the terminal velocity of water.
It depends if your falling faster or slower than the rate that water falls at. If the lavatory is falling faster than the water would be if you poured it out then the water would go up but if it’s a slow elevator fall then the water would go to floor like normal. Same way that if you jump while an elevator is falling very quickly you will go to the ceiling of the elevator
Einstein once said that his most happy thought was that of a man falling off a high building.. This wasn’t some morbid did entertainment from another Man’s demise. He thought it was neat that everything that everything that fell along with him would essentially be weightless from his perspective.
So for the water to hit the roof, the acceleration of the elevator has to be greater than the acceleration due to gravity. this is because the water in the bottle will leave it at the same speed as the elevator, and will accelerate at the acceleration due to gravity. So if the water and the elevator both fell at the same speed then the water would appear to float with respect to the elevator, but if the elevator is accelerating faster then the water than the water would hit the roof.
However, in most situations, the elevator is also subject to friction due to it’s rails and other mechanisms, so the water will fall on the floor.
This experiment is sort of done commonly on the Drop towers that are at popular amusement parks.
Power Tower at Cedar Point is a big one on physics day to show stuff like this. usually with someone holding a plastic tube filled with something. a object or water, bubble. I tried looking on youtube for the video but the quality was baddd
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