Like all ballistic missiles, the old Polaris missiles and the current Trident missiles use internal gyros for stability in flight.
Fins are used to help keep a rocket stable. The only way to find out if more fins will make it more stable is by testing it.
Guided missiles have small fins or wings attached to them, and use them to alter the aerodynamics of the missile, in the same way that a plane with wings (and aerilons/flaps) does. The difference is that in a missile, the small fins/winglets aren't providing lift of any sort (the missile body does that, combined with the very high thrust of the motor engine), and are merely steering. So, a missile flies through the air using the same principles as an aircraft.
It would not be so stable
Having fins will give you more control. Without fins you will be able to do surface 180's easier and landing tricks will be a little more forgiving.
because if thay are in the wrong place the rocket will not be stable
To remove surfboard fins, first, place the board on a stable surface with the fins facing up. Use a fin key or a screwdriver, depending on the fin type, to loosen and remove the screws securing the fins. Gently pull the fins out of their boxes or slots. If the fins require a specific removal technique, refer to the manufacturer's instructions for guidance.
Without fins, fish would not be able to move around (swim) and live.
It is possible for a fish to survive without its front fins, but it may face challenges with swimming, balance, and catching prey. The fish may need to adapt its movements and behaviors to compensate for the loss of its fins.
when people capture sharks they cut off their fins and then release them back into the water for dead because sharks can't swim without fins so they sink to the bottom of the ocean to drown because they have to come up for some air sometime but can't without fins
In order to stabilize them during their flight. Actually, that's not quite right. Missiles have movable "wings" (a better term for them is "fins"), whose primary purpose is to steer the missile onto target. Most missiles' fins are attached to the main body on a small rotating disk. The missile's guidance package sends commands to each fin, rotating the entire fin up or down slightly, to change the airflow over the fin, and thus change direction of the entire missile. Standard dumb bombs have fins which are not movable, and serve to stabilize the bomb when dropped, in the same way that feathers on an arrow stabilize it in fight. Modern "smart" bombs work identically to missiles, minus the rocket motor.
Water rockets need fins because the rocket needs to stay in balance....without fins on a water rocket, the water rocket would be going out of control because it is not in balance!
No. all fish need fins to swim. Or they would just stay at the bottom of the tank and die.