Gravity!

Thanks for visiting! Maybe you you read the article "Gravity Water Drop" in a magazine or online somewhere? Either way, thanks!

I posed a question in the article wondering why different things fall at the same speed sometimes, and other objects don't. 

Take for example a rock and a ping pong ball. If you drop those from the same height at the same time, they will hit the ground at the same time! They have different weights, too. Some people think that if something is heavier it always falls faster! Nope. Gravity affects all things the same way. 

But what about a piece of paper and a book? Surely you know a piece of paper drifts like a leaf to the ground while a book goes faster? That is because of the air getting in the way. If something is lighter, it is affected by air more. 

Question: 

How can you make the paper and book fall at the same time? 

Scroll down to see some answers!

Try: 

Put the piece of paper flat on top of the book and drop them! The book cuts through the air and so the piece of paper sticks to it! 

You can also crumple the piece of paper into a ball. Now there is less air touching the paper so it is more "aerodynamic."  

Egg in a Bottle Science Experiment

Here is a quick video showing how air pressure can affect things

Newton's First Law of Motion...Quick Demo

Newton's First Law of Motion states that: "An object in motion stays in motion and an object at rest stays at rest unless acted upon by an unbalanced force."

That ball bearing in the video wants to remain in place (it has what is called "inertia") but only if you can overcome the force of friction between the ball and the playing card.

If you move the card slowly, you don't overcome the force of friction and the ball moves with the card.

The same thing happens when you pull a sheet of paper out from under a book. Or even a tablecloth from under a place setting... Don't try that at home!

Have any other demonstrations that apply to this principle?