speed of falling objects?

Question

i read a newspaper today. its talks about a falling feather hits the ground in the same time as a falling rock in vacuum. i thought about that for quite some times. i don't really get it. a feather falls slower than a rock cuz of air resistance. if a rock falls faster even with air resistance, it should fall even faster without air resistance. so is that mean the speed of gravity constant?

damn i see some typo there and i cant edit my question.

if gravity is constant, does that mean all objects in vacuum fall at maximum speed?

i know in vacuum theres no air resistance. if a rock falls faster than a feather, then in vacuum, the rock should also fall faster than a feather. a feather falls faster in vacuum cuz it has no air resistance, but the rock also has no air resistance too.

ok i think i got some ideas.

Answer 1

A vaccum is in outer space or in some chamber on earth where all the air has been sucked out of. In either case there is no air resistance because there is no air so I think both should fall at the same rate.

It goes back to the guy that droped two balls of different weights off a tower and they hit the ground at the same time.
Thats my best guess anyways hope this helps.

Answer 2

Well the rock is less effected by the air resistance, this is why it falls faster. When in a vacuum, mass doesn't matter though. It is kind of hard to understand because you know if you were to drop a feather and a rock from the top of the Empire State Building, that the rock would land long before the feather.

The reason the feather takes so long is because of how much the air resistance effects it. The feather reaches its terminal velocity. Terminal velocity is the speed at which the force of air resistance = weight of feather. If we were to sum the forces in the y on the feather, we get Far going up, and Weight going down. We know that the Sum of the Forces = ma. If the forces are equal, 0 = ma, so acceleration equals zero. Without that air resistance holding it back there is only one force acting on it, the weight.

So if:
w = ma
and w also = mg, we can plug in:
mg = ma
now we can cancel out the masses
g = a
So the objects acceleration is just gravity. This is also true for the rock, so they both fall at the same speed.

Hope this clears up any trouble you have with understanding this.

Answer 3

You're basically right--both the rock and the feather fall faster in a vacuum than they do in the air. However, the CHANGE in speed is more for the feather than for the rock.

Look at it this way: If you drop a rock in the air, it might go maybe 97% as fast as it would in a vacuum. If you dop a feather in the air, it might go only 10% as fast as it would in a vacuum.

Now take them both to a vacuum. The rock falls a _little_ faster, and the feather falls a _lot_ faster. The result is that they both end up falling at the same rate.

Answer 4

Gravity does not have a "speed". Gravity is an attractive force. It causes objects to accelerate towards one another at a specific rate, but gravity does not have a rate itself. On Earth, the acceleration due to gravity is roughly 9.8 m/s^2, depending on where you are. This means that if you drop an object from a tall building, its velocity will increase by 9.8 meters per second, every second, until it reaches terminal velocity or comes in contact with the ground. Terminal velocity has to do with drag, which only occurs in a fluid, such as the atmosphere, and therefore would not affect the rock or feather in the vacuum.

In a complete vacuum, there is no air resistance, therefore all objects will accelerate at the same rate, and therefore travel the same distance in the same amount of time, meaning the rock and feather both hit bottom at the same time if released from the same height.

In the atmosphere, obviously there is much higher drag on the feather due to its large surface area compared to its small mass, meaning the rock hits first.

Answer 5

The acceleration due to gravity on an object is constant on earth at 9.8 meters per seconds squared. A rock falling does encounter air resistance but it is negligible . The affect of air resistance on a feather however is much greater due to its mass and surface area. This principle is better explained on an object with the same mass when confusion sets in. For example, a piece of notebook paper wadded into a ball and one that is normal. When dropped in the presence of air resistance the balled up piece of paper will fall faster. In a vacuum (no air resistance) they will fall at the same rate of acceleration.

Answer 6

The newspaper is correct. In a vacuum there is no air, hence there is no air resistance. The acceleration of gravity is the same for the rock and the feather. They would reach the ground at the same instant.

Answer 7

specific, they might have distinctive terminal velocities. right here is why... In a gas, the acceleration in loose fall is chanced on via a = g(a million - D/W); the place g = GM/R^2 is the gravitational container (e.g., 9.eighty one N/kg close to Earth's floor), D = a million/2 rho Cd S v^2 is the drag on the falling merchandise, and W = mg is the object's weight. rho is the mass density of the gas (e.g., air), Cd is the coefficient of drag the place a smaller fee skill extra streamlines, and S is the bypass sectional floor area of the falling merchandise. For simplicity anticipate the burden of the ball and of the spear is the comparable. What differs are the respective drags for the ball D and d for the streamlined spear. Terminal velocity for the two gadgets is reached whilst A = 0 = a; which skill neither is accelerating in its fall. so we are able to write a million - d/W = a million - D/W or d = D, the respective drags ought to be the comparable whilst their respective weights are the comparable. however the spear is streamlined so its coefficient of drag cd < Cd the coefficient of the ball this isn't streamlined and the spear's bypass sectional floor area s < S is decrease than the ball's. this implies for d = D, the spear's velocity (terminal velocity) ought to be extra advantageous than the ball's to yield the comparable drag. we are able to make certain this via writing d = kV^2 = Kv^2 = D, the place the respective ok's characterize the climate Cd, cd, S, and s that are merchandise particular and the a million/2 and rho that are no longer. ok < ok; so V^2 = (ok/ok)v^2 and V = v sqrt(ok/ok) and as ok/ok > a million.00 for sure V > v. The spear desires to bypass speedier to have the comparable drag because of the fact the ball.. observe, whether the gadgets do no longer attain terminal velocity (e.g., they are dropped from an altitude too low to upward push as much as terminal velocity), the spear will enhance up speedier as A = g(a million - d/W) > g(a million - D/W) = a so their result velocities may well be V = sqrt(2AH) > sqrt(2aH) = v the place H is the drop altitude. In different words, the spear might hit the floor first if the two gadgets have been released concurrently whether neither has reached terminal velocity.

Answer 8

The greater somethings mass the greater the gravitational pull will be.

However, the greater the mass the harder it is to move it.

These two values exactly cancel each other out, and that is why (in a vacuum) all objects fall at exactly the same rate.

Answer 9

Yes, the force of gravity is nearly constant. Varies with the distance from the center of earth. ~
Galileo was the one to prove that 2 objects of different weight would drop at the same speed and hit the ground simultaneously..

Answer 10

Newton,showed,by use of a vacume tubes,a feather and a metal ball fall together ., .Appolo 11 on the moon repeated this very beautifully !,
expriment rulles for ever.