Weight

Explore the relationship between drag and weight by experimenting with air resistance and vacuums. 

Transcript

Hi my name is Crystal, and I'm an Explainer here in the National Air and Space Museum and today we're here in the "How Things Fly" gallery to do some experiments to learn a little bit more about the concept of weight.

Now, what exactly is weight, and how does it affect us here on earth and things that are flying? Well, weight happens to be one of the four forces of flight that allow our objects to fly through the air but it's a little bit different from the other three, because, whereas the others requires some physical contact with the object, weight doesn't necessarily have to be touching the object that it's having an effect on because it's a field force.

Basically, all it is the gravitational pull on an object from the center of the Earth, so simply put weight is the mass of an object times the gravitational acceleration that we have here on Earth.

But did you know that if you were to measure your weight at the top of a mountain, and then measure your weight at sea level that you would actually weigh slightly less at the top of the mountain than you would at sea level? Because the further away you are from the center of the earth the less gravity there is pulling on your mass.

But now that we understand a little bit more about weight let's test out this concept a little bit. Here I have two objects I have a golf ball and a ping-pong ball. Now obviously the golf ball has a lot more mass than the ping-pong ball but, since gravity pulls at all objects at the same velocity, which one do you think is gonna hit the ground first? Do you think the golf balls gonna hit first? Or maybe the ping-pong ball is gonna hit first? Or maybe they're gonna hit the table at the same time? Well let's see what happens. When I hold them at the same height and release...

[golf ball and ping-pong ball drop]

They hit at the exact same time! Let's try one more time just to make sure. Hold them at the same height and release.

[golf ball and ping-pong ball drop]

Still they hit at the exact same time and that's because regardless of the mass of these objects gravity is still pulling on both of them with the same velocity and so they hit the table at the exact same time.

Now what would happen if I switched out one of these objects? I'm gonna switch out my golf ball for this feather and I'm gonna drop the feather at the same time that I'm dropping the ping-pong ball. Now based on what we just learned gravity is still going to pull on these two objects with the same velocity, so they should hit at the same time right?

Well let's see what happens. If I hold them at the same height and release...