Gun-loving India 'god-woman' shoots wedding guests

[pErvinalia]

The main reason that smaller bullets are unlikely to cause harm is down to the way that surface area increases with size. As things get bigger the weight increases far faster than the surface area. So if you had two perfect spheres of lead of different sizes, and dropped them from a height, the big one would fall faster because the drag would be less in relation to it's mass.

Acceleration, and therefore velocity, has nothing to do with mass.

[mistermack]

Acceleration, and therefore velocity, has nothing to do with mass.

The velocity has nothing to do with the acceleration.

You're talking about the final velocity, which is reached when the downward pull due to it's mass exactly balances out the upward drag. At that point, acceleration is zero.

[Jason]

[Jason]

The main reason that smaller bullets are unlikely to cause harm is down to the way that surface area increases with size. As things get bigger the weight increases far faster than the surface area. So if you had two perfect spheres of lead of different sizes, and dropped them from a height, the big one would fall faster because the drag would be less in relation to it's mass.

Acceleration, and therefore velocity, has nothing to do with mass.

When accelerating under gravity in a vacuum that's true, but it's not true in a fluid like the atmosphere of our planet.

[Seth]

The main reason that smaller bullets are unlikely to cause harm is down to the way that surface area increases with size. As things get bigger the weight increases far faster than the surface area. So if you had two perfect spheres of lead of different sizes, and dropped them from a height, the big one would fall faster because the drag would be less in relation to it's mass.

Acceleration, and therefore velocity, has nothing to do with mass.

When accelerating under gravity in a vacuum that's true, but it's not true in a fluid like the atmosphere of our planet.

Not quite correct. In a fluid it's not mass that determines drag, it's surface area. A balloon might have the same surface area as a sphere of lead but both have the same coefficient of drag in a fluid. Or as Mythbusters showed, you CAN make a lead balloon float in air.

That being said, acceleration due to gravity in a fluid is a function of both mass and surface area.

[JimC]

The main reason that smaller bullets are unlikely to cause harm is down to the way that surface area increases with size. As things get bigger the weight increases far faster than the surface area. So if you had two perfect spheres of lead of different sizes, and dropped them from a height, the big one would fall faster because the drag would be less in relation to it's mass.

Acceleration, and therefore velocity, has nothing to do with mass.

When accelerating under gravity in a vacuum that's true, but it's not true in a fluid like the atmosphere of our planet.

Not quite correct. In a fluid it's not mass that determines drag, it's surface area. A balloon might have the same surface area as a sphere of lead but both have the same coefficient of drag in a fluid. Or as Mythbusters showed, you CAN make a lead balloon float in air.

That being said, acceleration due to gravity in a fluid is a function of both mass and surface area.

Better to say that acceleration due to gravity in an atmosphere is a function of 2 variables:
1. The overall downwards force, which is the weight force minus the force of air friction
2. The mass
Acceleration, of course, = net force divided by mass. As the speed of a falling object increases, so does the frictional force. When it becomes equal to the weight force, and thus net force = 0, no further acceleration occurs, and terminal velocity is reached.

[Seth]

The main reason that smaller bullets are unlikely to cause harm is down to the way that surface area increases with size. As things get bigger the weight increases far faster than the surface area. So if you had two perfect spheres of lead of different sizes, and dropped them from a height, the big one would fall faster because the drag would be less in relation to it's mass.

Acceleration, and therefore velocity, has nothing to do with mass.

When accelerating under gravity in a vacuum that's true, but it's not true in a fluid like the atmosphere of our planet.

Not quite correct. In a fluid it's not mass that determines drag, it's surface area. A balloon might have the same surface area as a sphere of lead but both have the same coefficient of drag in a fluid. Or as Mythbusters showed, you CAN make a lead balloon float in air.

That being said, acceleration due to gravity in a fluid is a function of both mass and surface area.

Better to say that acceleration due to gravity in an atmosphere is a function of 2 variables:
1. The overall downwards force, which is the weight force minus the force of air friction
2. The mass
Acceleration, of course, = net force divided by mass. As the speed of a falling object increases, so does the frictional force. When it becomes equal to the weight force, and thus net force = 0, no further acceleration occurs, and terminal velocity is reached.

I'm not sure that's correct. A parachute, when packed, has mass X and surface area A, whereas when opened it still has mass X but now it has surface area B, and descends much more slowly as a result of that expanded surface area and its effects on fluid drag.

[pErvinalia]

Acceleration, and therefore velocity, has nothing to do with mass.

The velocity has nothing to do with the acceleration.

Of course it does. Things don't just obtain a velocity. They have to accelerate from rest.

You're talking about the final velocity, which is reached when the downward pull due to it's mass exactly balances out the upward drag. At that point, acceleration is zero.

I'm talking about your suggestion that velocity and acceleration has something to do with mass. It doesn't.

[pErvinalia]

The main reason that smaller bullets are unlikely to cause harm is down to the way that surface area increases with size. As things get bigger the weight increases far faster than the surface area. So if you had two perfect spheres of lead of different sizes, and dropped them from a height, the big one would fall faster because the drag would be less in relation to it's mass.

Acceleration, and therefore velocity, has nothing to do with mass.

When accelerating under gravity in a vacuum that's true, but it's not true in a fluid like the atmosphere of our planet.

You are talking about terminal velocity. MM didn't say terminal velocity. He said velocity alone.

[JimC]

Seth wrote:

I'm not sure that's correct. A parachute, when packed, has mass X and surface area A, whereas when opened it still has mass X but now it has surface area B, and descends much more slowly as a result of that expanded surface area and its effects on fluid drag.

You (as often happens) have missed my point. I was saying nothing about the factors which affect the force of air friction on a given object (other than speed; the frictional force is, as I'm sure you know, proportional to the cube of the speed)

What I was discussing was how weight force and a given frictional force interact during falling to produce a particular terminal velocity. A good example is comparing a normal ping pong ball (filled with air) and an identical ball, filled with lead. Since they have the same size, shape and surface texture, at any given air speed both will experience the same frictional force. However, the normal ball's weight force is very low, so it reaches its low terminal velocity within a metre or two. The other will keep accelerating for much longer, reaching a much higher terminal velocity.

As to the factors intrinsic to an object which control its air resistance, they include cross-sectional area (which of course is the dominating factor in your parachute example), shape and surface texture. The external factor of air density also has its effect.

[Alan B]

So, what's happened to this 'God-Woman'?
And have the authorities ascertained which gun(s) fired the lethal shots?

[pErvinalia]

[Indian head wobble]

[Alan B]

[Indian head wobble]

That means 'Yes'!

[mistermack]

You are talking about terminal velocity. MM didn't say terminal velocity. He said velocity alone.

I assumed that you understood the bleedin obvious. Sorry.

For your information, if you shoot a bullet straight up, when it comes back down to Earth, it will ALWAYS be travelling at terminal velocity. The acceleration will have stopped long before it lands.
So when the bullet hits you on the head, the only factors influencing the damage it will do are it's mass and it's drag. Because it's mass is proportional to both it's momentum and it's terminal velocity.

[Seth]

So, what's happened to this 'God-Woman'?
And have the authorities ascertained which gun(s) fired the lethal shots?

She's been charged with murder.