## Physhics question

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stinkychops
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Response to Physhics question 2012-04-29 06:56:15

At 4/29/12 05:19 AM, tox wrote:
At 4/29/12 05:15 AM, stinkychops wrote: My point was that if its mass were half that of earth it would exert a force upon Earth towards itself, reducing how long it takes to meet.
your dropping a moon on earth and your dropping a different item.. the two will not hit at the same time.. object A and object B will not hit C
A and B will hit and object B will hit C....
stay to the OPs idea.. 2 balls 1 tonn and 1.5 kgs...
speed, resistance, and time

(go back and read my post... it will tell you exactly what you are arguing about right now)

You're assuming they're dropped at the same time.

Also I wasn't talking to you. OP's post has already been resolved.

i-am-ghey
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Response to Physhics question 2012-04-29 08:07:02

At 4/28/12 09:21 PM, NinoGrounds wrote: Object A has mass 1t, and object B has mass 5kg. They have the same radius, i.e. they are identical in outer shape. They are released from 24km altitude, on Earth. Will they hit the ground at the same time?

if air resistance can be ignored, the two objects will hit the earth at the same time, regardless and mass and shpae.

if air resistance has to be taken into account, the heavier one will hit the earth earlier because it has a higher terminal velocity.

(F=bv, if m is larger, v is larger)

anyone that tells you otherwise is an idiot. the end.

I am just a random user from a set of measure zero and thus am negligible.

Gramiscus
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Response to Physhics question 2012-04-29 09:27:03

At 4/29/12 04:59 AM, Xenomit wrote:
At 4/29/12 04:56 AM, daethdrain wrote: Remember this and you'll go places.
you'll go straight to the hospital when I beat you up, you big dummy
Oh yeah, well then can you tell me at what point the center-phaze of all mater reaches sub-atomic levels?!?!?

I DON'T NEED YOU TO, BECAUSE I KNOW IT

We have established on this forum that you have a PhD in cockery, but please elaborate on what you mean. Maybe we can have an intellectual discussion.
and don't hold back.
or i will make fun of you.

I go to school to study how high frequency sound waves can heal, ...or KILL.

FanofFulp
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Response to Physhics question 2012-04-29 09:42:45

At 4/29/12 04:42 AM, Xenomit wrote: 2. I deal with theoretical physics and such, I suck at math

theoretical physics still uses a great deal of complex mathematical concepts. so i'm guessing you don't deal with theoretical physics and such but like to say you do.

Gramiscus
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Response to Physhics question 2012-04-29 09:54:17

I go to school to study how high frequency sound waves can heal, ...or KILL.

Zirocket-8
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Response to Physhics question 2012-04-29 10:03:47

At 4/28/12 09:21 PM, NinoGrounds wrote: Object A has mass 1t, and object B has mass 5kg. They have the same radius, i.e. they are identical in outer shape. They are released from 24km altitude, on Earth. Will they hit the ground at the same time?

If they are released at the same time, they will fall at nearly the same time, regardless of the mass. When you say "radius" I will assume that the shape is a sphere.

All elites originate from noobs.

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Thedark
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Response to Physhics question 2012-04-29 11:34:50

They will hit the ground the same time

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SantoNinoDeCebu
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Response to Physhics question 2012-04-29 11:43:31

At 4/29/12 05:01 AM, RamzaX0 wrote: The weight does not matter. Since they both have the same shape, they would fall at the same time

Would a feather shaped rock float to earth at the same rate as a.. feather shaped feather?

Evark
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Response to Physhics question 2012-04-29 13:14:32

We need more information to accurately answer this question. There are two possible outcomes: they land at the same time, and the heavier object lands first. The former outcome will be the case up to and including the lighter object's terminal velocity. The latter will occur whenever the height from earth is such that the lighter object's terminal velocity has been met and they have not hit the ground. The heavier object's mass will allow it to reach a greater terminal velocity against the wind resistance in the fluid that the objects are traveling through.

i-am-ghey
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Response to Physhics question 2012-04-29 13:29:39

At 4/29/12 01:14 PM, Evark wrote: The former outcome will be the case up to and including the lighter object's terminal velocity.

i am not if i understand the point.

actually, you should look at the acceleration of both objects. one can show, from elementary calculus, that the displacement of the lighter object is always smaller than that of the heavy object at any given instant.

in this case, one can guess from the terminal velocities that the heavy object will land first because of the great falling distance and extreme difference in density.

I am just a random user from a set of measure zero and thus am negligible.

i-am-ghey
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Response to Physhics question 2012-04-29 13:45:07

At 4/29/12 01:33 PM, Xyphon202 wrote:
The equation for terminal velocity has the mass at the top of a fraction in an equation and the density at the bottom.
As mass = volumexdensity, the mass and density are therefore proportional on objects that are the same size (i.e. the same volume). So if one has a mass of 20 and a density of 5, if the other one has a mass of 40 its density will be 10, so the terminal velocity will be the same.

great, you learn something new everyday. i learnt it as F=bv in secondary school and i don't realise b is mass dependent.

but still, i am guessing from the expression of net force that the lighter mass will reach the ground earlier, because the object could be reaching the terminal velocity sooner.

i don't know how to solve it analytically though.

I am just a random user from a set of measure zero and thus am negligible.

i-am-ghey
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Response to Physhics question 2012-04-29 13:46:47

At 4/29/12 01:45 PM, i-am-ghey wrote:
but still, i am guessing from the expression of net force that the lighter mass will reach the ground earlier, because the object could be reaching the terminal velocity sooner.

i don't know how to solve it analytically though.

forget it. it is the acceleration that matters. it should be the same.

I am just a random user from a set of measure zero and thus am negligible.

Buoy
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Response to Physhics question 2012-04-29 14:02:28

Isn't this pretty simple?
- The forces that act on the balls are a. gravity and b. air resistance
- We all agree that the balls experience the same acceleration due to gravity.
- The balls have the same shape, so they experience the same force from air resistance.
- per Newton's second law, the same force will cause greater acceleration on an object with less mass.
- air resistance acts upwards in this case, so the 5kg ball experiences a larger acceleration upwards from the same force since it has less mass than the 1t ball.
- the total acceleration downwards is greater for the 1t ball. It lands first.

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Response to Physhics question 2012-04-29 14:09:48

You can't even spell Physics right. You have no hope for solving this incredibly complex and college-level problem.

i-am-ghey
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Response to Physhics question 2012-04-29 14:12:08

haha, guess what i found. i was right.

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Evark
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Response to Physhics question 2012-04-29 14:25:04

At 4/29/12 01:33 PM, Xyphon202 wrote: The equation for terminal velocity has the mass at the top of a fraction in an equation and the density at the bottom.
As mass = volumexdensity, the mass and density are therefore proportional on objects that are the same size (i.e. the same volume). So if one has a mass of 20 and a density of 5, if the other one has a mass of 40 its density will be 10, so the terminal velocity will be the same.

Except that the density the equation is referring to is the density of the fluid the objects are contained within, not the density of the objects themselves. Terminal velocity is not the same for objects of the same volume and shape when they have a differing mass.

thespammer
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Response to Physhics question 2012-04-29 14:50:15

Why? are you trying to catch both of them with your asshole?

that is sooooooo hawt! <3
i-am-ghey
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Response to Physhics question 2012-04-29 21:06:25

it is certainly not a trivial statement. suppose resistance is a function of v.

mg-f(v)=ma=m(dv/dt)
(dv/(mg-f(v))=(1/m)dt

let F(v) be the antiderivitive of 1/(mg-f(v)) => F(t/m)=v(t)

for the lighter mass, F(v) is greater for same v and hence F^(-1)(t/m)=v(t) is smaller for same t, assuming F is bijective.

integrating bothe sides with respect to t, one can arrive at the result that the ighter object always reach earth first.

done.

I am just a random user from a set of measure zero and thus am negligible.

i-am-ghey
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Response to Physhics question 2012-04-29 21:08:01

At 4/29/12 09:06 PM, i-am-ghey wrote: stuff

heavier object always reaches earth first.

I am just a random user from a set of measure zero and thus am negligible.