What is a free fall?

by Carson
315 views
Free Fall?

When you release a thing from the air, it accelerates until it hits the ground hard. So, what is a free fall and its features?

A Free Fall

It turns out that an absolute free fall is when only gravity is acting on it, not including drag. For example, if you just failed to hold onto a book, it immediately accelerates due to gravity, but it’s not free falling. In fact, if you’re holding onto something, you are fighting the gravity by friction!

When a free fall occurs upon an object, its velocity is solely affected by Gravity. That’s why we can use a falling speedometer and timer to find out Earth’s gravitational acceleration rate. Remember that the weight of an object doesn’t affect the acceleration, but only the ratio of drag acting on it. Regardless, if an object stops picking up speed and decelerates when an object is descending, that’ll mean it isn’t in free fall, due to air resistance.

The motion of free falling objects
Credit: NASA Glenn Research Center
URL: https://www.grc.nasa.gov/www/k-12/airplane/Images/mofall.gif

Special Cases

Well, is Earth in free fall? Most people would answer, ‘no’, because they don’t know the real situation. In reality, our planet is in that state, but is falling around instead of descending toward the Sun. When an object is traveling so fast that the momentum to escape and the host’s gravity levels, it is taking a circular path. Even if it is going up, it can be considered in that state if nothing acts on it except gravity.

How an orbit works
The screenshot for Earth is taken from NASA’s Eyes

Also, the definition of a free fall in everyday life may not be that strict. Falling without a parachute or in space are still considered free falling while it physically isn’t because a true ‘free fall’ is when an object is falling through a vacuum, without any particles hitting it! Therefore, falls with terminal velocity doesn’t count.

Free Fall and Weightlessness

Have you ever seen astronauts walking on a space shuttle due to gravity? Probably not. Although they have a theoretical weight, it can’t be measured on a scale, or felt by humans. That’s because astronauts, as individuals, are orbiting Earth on their own. They’ve already reached a balance between the momentum outward and inward. Furthermore, we can see astronauts floating relative to the background because they take a slightly different orbit. Moreover, we perceive the force that the ground or any other object pushes on it and the balance with gravity as weight.

References, Credits, and Links

  1. (2020, October 19). Free fall – Wikipedia. Retrieved November 16, 2020, from https://en.wikipedia.org/wiki/Free_fall
  2. (2015, May 5). Free Falling Object Motion – NASA. Retrieved November 16, 2020, from https://www.grc.nasa.gov/www/k-12/airplane/mofall.html
  3. (2018, October 18). Free Falling: the science of weightlessness – Science in the news – Retrieved November 16, 2020, from http://sitn.hms.harvard.edu/flash/2018/free-falling-the-science-of-weightlessness/

Related Posts

Leave a Comment

* By using this form you agree with the storage and handling of your data by this website.