Why do PROJECTILES tend to posses a rotary motion in order to stabilize themselves in AIR ?

Why do the things like Ball, missiles Spin to stabilize when thrown in Air??

Why do Earth rotates around it's axis when it orbits the SUN??

Why the things try to rotate when they are in motion...

Please Give a detailed understandable explanation with real references.Why do PROJECTILES tend to posses a rotary motion in order to stabilize themselves in AIR ?missiles spin because it gives them angular momentum, and it takes force to change angular momentum, therefore it makes the missiles tend to stay more on the axis of angular momentum.



the earth spins on its axis because there is momentum left over from when it formed



things in general spin to keep their center of mass on a smooth trajectoryWhy do PROJECTILES tend to posses a rotary motion in order to stabilize themselves in AIR ?Why do PROJECTILES tend to posses a rotary motion in order to stabilize themselves in AIR ?

Why do the things like Ball, missiles Spin to stabilize when thrown in Air??

Why do Earth rotates around it's axis when it orbits the SUN??

Why the things try to rotate when they are in motion...





http://en.wikipedia.org/wiki/Inertia

From web site above

Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion.



http://en.wikipedia.org/wiki/Moment_of_i鈥?/a>

From web site above

In classical mechanics, moment of inertia, also called mass moment of inertia, rotational inertia, polar moment of inertia of mass, or the angular mass, (SI units kg鈥虏) is a measure of an object's resistance to changes to its rotation. It is the inertia of a rotating body with respect to its rotation. The moment of inertia plays much the same role in rotational dynamics as mass does in linear dynamics



Momentum is always conserved.

Angular momentum = moment of inertia * angular velocity

If the object is a cylinder rotating around a line through the center, moment of inertia= 陆 * mass * radius^2

Angular momentum = 陆 * mass * radius^2 * angular velocity



When a bird hit hits the rotating cylinder, the force on impact is attempting to change the direction of the cylinder鈥檚 angular velocity and/or linear velocity

As the angular velocity increases, the angular momentum increases. Larger angular momentum means the force will produce less change in the total momentum of the cylinder.



Wind and rain, and birds will always try to affect the motion of a projectile. The way to decrease their effectiveness is to increase the rotational inertia of the projectile.



This is how rotation increases the stability of the projectile !