Physics question

[mosdef]

How can I show that gravity does not have any direct effect on horizontal movement? In other words, objects have unique vertical and horizontal movements that aren't directly linked.

-mosdef

 

[ArkAoss]

like in an equation?? what to do to represent it?

 

[006agent]

nice try..you can't

if you shoot a bullet at 1100 fps
and you shoot another bullet at the same time at 900 fps

both 4 feet of the ground.

the bullets will hit the ground at exactly the same time..gravity is relative.

 

[mosdef]

Yeah but one will travel farther than the other... that's what I meant.

-mosdef

 

[Capn]

The best recommendation I could give you is to start using the gravitational force equation which is F=m*M*G/r^2 That force is a vector component and the direction is towards the mass center of the earth (down). For examples sake you could show that the dot product of the vector gravitational force and a unit vector in the horizontal direction is zero. Therefore you could say that you can define two discrete axes one in the same direction as the gravitational force vector and one normal to that vector in which no components of the gravitational force vector exist.

Other than that, I'm not sure.

 

[ApacheXMD]

because the force vector that gravity causes is perpendicular to "horizontal". therefore no component of a horizontal force will affect the gravity vector.
it's just pretty much common sense, i think.

-patchy

 

[EpsiIon]

Here's the best way to demonstrate (not prove) it. Push a ball off a table at whatever speed you'd like and, just as it's going off the table, drop another one from the same height as the table. They will hit the ground at the same time.

 

[UG]

I take this question to mean "How can I show that a gravitational vector cannot produce in an object motion perpendicular to itself?"

Since a gravitational vector arises from a concentration of mass -- a mass built of particles thought to be imbued with the quality of mass by the Higgs Boson, and since no known mass is without the quantitative quality of spin, and since any object constantly under the influence of a gravity vector describes an orbit with a circular component around a rotating mass, the way for a gravitational vector to not produce in an object perpendicular motion (motion with some sort of circular component) is if the object is so far away from the gravitating mass that the influence of the gravitational vector is statisically inconsequential to the straight line path of the object, as if the gravitational vector did not actually exist.

 

[KMurphy]

The horizontal and vertical movements are directly linked. The reason a force perpendicular to a direction is zero is because the cos(90)=0. If you break each force into its component vectors, this relationship is intuitively obvious.

 

[jyrixx]

my high school physics teacher always said horizontal had nothing to do with vertical. simple as that. symbolically, there isn't a way to prove it. so i'm agreeing with apache.

 

[Capn]

You can definitely prove it, all axes are arbitrary anyways. It's just easier in highschool physics to define your axes as horizontal and vertical with respect to the apparent plane of the earth's surface.

 

[UG]

<... all axes are arbitrary...>

As are all hatchets.

 

[006agent]

the only way an object can retain movement without relative loss of velocity and vector, is in a vaccuum........

all object fall under the same rules of gravity..therfore a object moving @ said speed will remain relative in vector if no other forces are present.......


good luck man.....