Welcome dear Steemians to another episode of Myth or Fact!
I promised you that I came back with more inspiration and new myths! Or are these facts? We will find out.
Consider the following scenario: After a long and boring day in the office you want to get as fast as possible home. You decide to take the elevator since your office is in the 75th floor. Just like every day the door opens, you step inside and see people smiling weirdly at you. You press the button which says “Ground floor” and there you go.
All of a sudden you hear a weird sound as in the lash of a whip followed by an eruption. The elevator doesn’t move. In the next moment the elevator is falling and you inside. You look death in the face and know nothing will help you. Suddenly you remember that jumping in the right moment will save you from the impact.
You survive.
A tale or scientific fact? Let's investigate!
We have to break down the described scene in order to understand what happens. The elevator as well as the person inside are both in free fall. What does that mean?
Every body that is only being acted by the gravity force is in the state of free fall. We will ignore the air resistance since it doesn’t have any huge impact in our description.
The elevator and the person both fall due to the force of gravity with a constant acceleration. The rate of acceleration is 9.8 m/s/s and mostly represented by the letter g.
You got it right, both objects fall with the same acceleration towards earth independently from their mass.
This formula explains why:
F = m * g
F is the force that acts upon the body, m is the mass and g is the acceleration of gravity.
After transforming the equation to: F/m = g, it is obvious that the acceleration is always the same. No matter what mass or force acts. (Note that the value of 9.8 m/s/s is for other planets different and only approximately 9.8)
This is one of the reasons why you cannot jump inside a falling elevator. Your body is in free fall and for a split second there is zero gravity.
Credits
Let us calculate how long it would take for an elevator to reach the ground when it starts to fall from 10 m.
We will use this simple equation.
h is our height, g as above the acceleration of gravity and t the time.
Having a height of 10 m the time until impact is 1.4 seconds. Not much time for people in a shock situation right? In our example however we said we are in the 75th floor, so we would have more time, right?
Let’s pretend the elevator falls with a speed of 60 km/h. In order to overcome its downward movement you would have to jump up with a speed greater than 60 km/h. That’s impossible.
Conclusion?
In case my elevator falls I will still give it a try. Science however taught us that it’s not possible and therefore there is nothing we can do in such a situation. Today’s lifts are safe and are provided with many emergency backup system that will avoid such a scenario.
Next time someone tries to sell you this myth, you know better now! Or perhaps already did? Let me know what you think or wish for the next episode of Myth or Fact!
Tim