how do i find the terminal velocity of a bullet?

Question

like the top speed or the angle/speed ratio.

Answer 1

Terminal velocity is the speed that a free falling body will reach when the drag in the air counteracts the force of gravity. A bullet is launched at a speed greater than that of sound in the air and will have it's maximum speed as it leaves the barrel of the gun. I don't believe the term can be applied to a bullet.

Answer 2

Terminal velocity means the velocity at the end, the terminus. In the end, a free falling body in a gas will have a terminal velocity when drag forces equal the force of gravity (Fd = W).

Drag forces are a form of friction forces that depend on the velocity, cross sectional area, and density of the gas. The direction of the forces is in the direction opposite to the direction the body or bullet, in your case, is moving.

At the point of terminal velocity, the net force on the falling body is zero because f = Fd - W = ma = 0 and the free falling body is no longer accelerating (a = 0). So, for this body, the terminal velocity is reached when it can go no faster, acceleration is zero.

Drag forces affect your bullet; so there is a slowing down effect due to drag forces. Thus, as one answerer put it, the maximum velocity would be just as the bullet exits the muzzle. After which, there is no more acceleration from the blast and there is deceleration from the drag forces.

But notice that gravity works on that bullet as soon as it leaves the gun. So in a very real sense that bullet is falling as soon as it leaves the barrel. The good news for the shooter is that the bullet goes so fast that it doesn't fall very far before it hits or misses the target. That is, the bullet doesn't usually stay in the air long enough to fall very far.

Answer 3

Well, you could drop it from a plane and measure it's speed. There's probably an easier and cheaper way though.

First, a review. Terminal velocity is the speed of an object when the gravational pull of the earth pulling it down and the air resistance fighting that force, equalize. And that point, an object -like a skydiver- fall at a constant rate. While all objects fall at the same rate in a vacuum, they do not tend to fall at the same rate in our atmosphere (a feather vs. a brick for example). So, your bullet has a certain resistance and mass falling through air that will affect and determine to a large degree, it's terminal velocity. Here's the equation:
Terminal Velocity = the square root of ( (2*mass*gravitational acceleration) / (gas density * crosssectional area of object * drag coeffecient)).

Plug in those numbers and you'll be pretty close. You'll have to get the rest from your physics book.

Answer 4

Velocity(terminal) = SQRT( (2W)/(Cd p A))

where
W = weight
Cd = Coefficient of drag
p = gas density
A = frontal area