|Do heavier objects fall faster than lighter objects?|
|Question Date: 2020-02-14|
Heavy objects fall at the same rate (or speed) as light ones. The acceleration due to gravity is about 10 m/s2 everywhere around earth, so all objects experience the same acceleration when they fall.
Acceleration is the change in speed in a second, so if all objects have the same acceleration, they experience the same change in speed. This fact was experimentally confirmed when the astronauts on the Apollo 15 mission went to the moon. One of the astronauts dropped a hammer and a feather on the moon, and they fell at the exact same speed! You can see the video here. A hammer and a feather on earth would probably fall at different speeds due to air resistance; however, if you had two balls of the same size, but one light and one heavy, you would see the same effect.
No, heavier objects fall as fast (or slow) as lighter objects, if we ignore the air friction. The air friction can make a difference, but in a rather complicated way. The gravitational acceleration for all objects is the same.
If two things are falling through a vacuum, they would have the same speed toward whatever object they approach because gravity would be the only force on the two things. In other words, if two things were falling through vacuum at the Earth, these two would fall toward the Earth at the same speed because Earth's gravity is the only force acting on the two. However, if two things are falling through the atmosphere of the Earth, the force from air resistance would also act on the things and slow them down. How much air resistance there is depends on a few things:
1) how fast the object is falling;
2) what the area on the object that air resistance is "dragging" (in many cases it's the area going against the air); and
3) how dense the object is.
If we assume that a lighter and a heavier object both start to fall at the same speed, have the same shape, and are the same size, then the heavier object will fall faster because it would be denser. If the lighter object is small, and the heavier object is big, however, we would have to figure out the density and area of resistance of each one before we can say which one falls faster, still assuming that they start out with the same falling speed.
Hello Aiden, your question is a good one and is one of the most commonly misunderstood ideas in physics and gravity-related concepts. The force that gravity exerts on a falling object is proportional to its mass (Force = a constant number * mass). On earth, that constant is given the letter g= 9.8 m/s2. That equation tells us that a heavier object is pulled more by gravity than a lighter one, which is why it's harder to pick up a heavier object than a lighter one. However, this doesn't not mean that either object will fall faster.
If we think of Newton's second equation: Force/mass= acceleration. We can see from this equation that even though a heavier object will experience a stronger force due to gravity, its acceleration will be the same as the lighter one since the force is also divided by the mass of the object.
For example, if I have an object 1 that is 5 kg and an object 2 that is 2 kg, let's say that the heavier object will experience g*5 = 5g N of force from gravity while the lighter one experiences g*2= 2g N of force. When we divide by each of their masses though, object 1 will have an acceleration of 5g N/ 5 kg = g m/s2 while object 2 will have an acceleration of 2g N/ 2 kg = g m/s2. As you can see, the acceleration of each object will be the same and we can say with confidence that if they are both dropped at the same time, their speeds will be the same. Thank you for your curiosity Aiden.
Are your objects in a vacuum or are they in a fluid? First off, what is a vacuum? A vacuum is a space with absolutely no matter in it: so no air, no water, nothing. Next, what's a fluid? A fluid is something that doesn't have a fixed shape and flows easily. Something like water or the air we breathe is a fluid.
If your heavy and light objects are in a vacuum, then they fall at the same speed. This is because they only have one force acting on them: gravity.
On the other hand, if your objects are in a fluid, then you'll clearly see that's not the case. If you have a rock in one hand and a piece a paper in the other, the rock clearly hits the ground before the paper fluttering down does. Why is that? It's because now there is more than one force acting on the objects. Not only do you have gravity pulling down on the objects, you now have the fluid resisting the movement against it. You can feel this resistance when you go swimming. If you move your hand quickly in water, it takes a lot of strength to keep it moving and it feels almost like you're pushing against something. That's called drag. You'll also experience this in air if you move your hand fast enough to feel the wind passing through.
I should also point out that the more surface that you can push on means that there's more area that your fluid can drag on. For example, if you have a sheet of aluminum foil and a sheet of paper of the same thickness, the aluminum foil is going to be heavier than the paper. If you crumple up your paper really small, then the paper's surface area changes even though the mass doesn't (the foil is still heavier than the paper). The paper ball now has a smaller surface area than the foil, meaning the air has less area to push against. So it would actually fall faster in fluid than the foil sheet, despite the foil being heavier.
Usually not. Galileo did a famous experiment on the Leaning Tower of Pisa when he dropped 2 cannonballs of different weights, and they fell at the same speed.
But things like balloons can float, because the air holds them up. So, things like feathers fall slower than heavier objects because the air holds them up.
You can do an experiment. Take 2 pieces of paper. Wad up 1 piece as tight as you can into a ball. Drop both pieces of paper. Does one fall faster? Do the 2 pieces of paper have the same weight or different weights?
Galileo Galilei, who lived in Pisa at the time, is said to have dropped two cannonballs of different masses from the tower to demonstrate that their speed of descent was independent of their mass.
That depends on whether or not you drop them in a vacuum. In a vacuum (on the moon, say), all objects fall at the same speed, even if one is heavier than the others.
In air (such as on Earth), the amount by which gravity moves heavy objects downward is the same as it is in a vacuum, but the air itself makes an upward force that slows the objects down, and the amount that air slows objects down depends on how heavy they are.
So, for example, if you drop a hammer and a feather at the same time, and are on the moon when you do this, they will hit the ground at the same time. The astronaut David Scott did this on the moon in 1971. If you did the same thing on Earth, though, the hammer would hit the ground first, because the air slows the feather down more than it slows down the hammer.
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