A Question about Object Motions [With thanks in advance]

[SEEKER]

Hello,,
I have a question that puzzle me for a long time!
This question is:
a- How an object -either metal or any thing- fly or move in air without changing in its direction.
b- what field of physics study such matters?
c- Is there any websites may give me detailed information about my question and its field?

Thank you very much.

[FZ+]

I am confused.
By Newton's 1st law, any object will either remain stationary or move in a constant velocity (and as vector, this includes velocity) unless there is a resultant force acting on it. Simple?

[SEEKER]

You only answer the first part of my question,,
anyhow, I meant how to make an object able to fly in a straight way in air, such as a good rocket?

Thank you very much

[enigma]

Its called aerodynamics.

NASA has a decent intro site here:

http://www.grc.nasa.gov/WWW/K-12/airplane/bga.html

with links to other related pages (like model rockets, etc.)

I'm studying it in school

http://www.enae.umd.edu

and there are lots of folks here who know about it, so ask away if you've got any specific questions.

[dr-dock]

actually it's quite simple.
consider a rocket going strait up.
we have three coordinates to consider:
(1)x-axis
F(x)=0
X(x)=Xmax
E(y)=0

(2)y-axis
F(y)=Fmax
X(y)=0
E(y)=0

(3)z-axis
F(z)=0
X(z)=0
E(z)=F(x)X(y)-F(y)X(x)=-Fmax * Xmax

Fmax is the gravity pull and Xmax is (R+h) the radius of the earth plus the height of the rocket.
why there is minus in front?
cause E(z) is the energy that the rocket gives to the outside.
-E(z)=Fmax*Xmax is the energy the rocket gets from outside.