A fly and a steel plate

My friend gave me this problem to solve cause why the fuck not. I'm stumped but I want to see if anyone here can solve it.

How fast would a housefly need to be traveling in order to puncture a 1.5in (3.81cm) thick steel plate?

Here's some constants for ya
Mass of fly: 21.4mg
Density of fly: 100kg/m^3
Density of steel: 8050kg/m^3

>so how about it anons?

Other urls found in this thread:

uintah.utah.edu/
scifiideas.com/science-2/scifi-weapons-ballistic/
youtube.com/watch?v=n9CKhOf3BzY
twitter.com/NSFWRedditVideo

At least over 100 mph, but probably not higher than 175mph.

potential hint: at high enough speeds anything is a fluid

I'd have to say faster than a speeding bullet, faster than Earth escape velocity even. The best solution is simply to test this by launching flies at steel plates at ever increasing velocities.

Alternatively, you could pussy out and do this in simulation using a code like uintah:
uintah.utah.edu/

pretty fast lmao

So like, if I know the cross sectional area of the fly, what properties of the steel would I need to know? Modulus of elasticity? Tensile strength? What things am I missing to be able to solve this?

Consider that a high pressure water jet traveling at 900 mph can only penetrate steel with abrasive material as an intermediate. At such high speeds the fly is essentially the same as shooting water at the steel. It can't be done with current technology and is probably impossible.

It's a hardness issue. The fly is not hard enough to penetrate steel at any speed.

So what you're saying is that since the the fly is not as hard as the steel, even at close to light speed, the steel would be able to absorb all of the momentum of the fly?

I feel like at some point the fly would be able to penetrate through the steel because at some point the steel wouldn't be able to absorb this momentum.

All that and what happens to steel when it vaporizes/melt. And some plasma metal interaction. Hmmm... That's probably going to be hard.

You'd best find some approximation.

If the fly is going at huge percentages of c it's going straight through

But for 'realistic' speeds, I'd say all we need to do for the fly to penetrate things is have it blow a hole through the other side and maybe throw a bit of fly plasma through the hole.

Let's take realism straight out of the equation. Even if it would need to go faster than the speed of light, I'm still looking for an answer.

We assume the fly keeps its same volume, same cross sectional area, and penetrates through the center of the plate. I'll look up some more info to try and help.

I need answers anons, I will biologically engineer this fly myself

>>Let's take realism straight out of the equation.
Ok your fly will pass through the wall and not pass through the wall depending on which reference frame you're in.

Assuming a fly made of tungsten, I'd say probably around 10 km/s, maybe 5 km/s

Can I use pic related to solve my problem? If not can I linearly interpolate the table in the next post to solve for tons of force?

Also the volume of a fly we can estimate to be 2.14E-7 m^3
And the cross sectional area could be estimated to be that of a sphere of about 5mm radius so about 7E-5 m^2

...

Using this equation, I got that the fly would need to be traveling at roughly 15.5km/s but this may not be correct seeing that the equation is specifically for "iron" balls so the fly obviously had a different density and moment of inertia and whatnot. Not sure how to get around this though

I think for all non-extreme velocities your fly is just going to splash itself on the plate. The forces holding the bits of the fly together just aren't strong enough to stop this from happening. I think this is really the factor that, ultimately, makes Newton's impact depth approximation and other such considerations you'd usually use for impact problems not apply.

But of course, you can shoot individual particles through steel plates, I think, if you accelerate them to relativistic speeds.

So, I think in this case the answer is that, due to the forces between the fly's particles being insignificant compared to the other forces present, you will basically have to treat the fly as an unbound collection of individual molecules/nuclei. You could then maybe estimate the velocity at which a single such nucleus would penetrate deep enough to pierce the plate. Of course, there's complications in that you might have several nuclei impacting the same spot and so on.

>Let's take realism straight out of the equation

What I meant by this is that we can assume that the fly stays together with constant mass, energy, velocity, so on even if these parameters do not come close to applying in the real world.

It's impossible for a fly to accelerate to 15km/s but I suppose we can assume that instead of a fly, it is some spherical mass with the same mass, density, and cross sectional area; one that will not break its molecular bonds upon impact.

So would there be a way to alter the equation above to match the density of this mass instead of iron?

Update: I found pic related
I'll see what I can cook up

UPDATE: I think I'm solid with this theoretical answer, check my work if you want to call me out on being a brainlet.

just remember ricks first law of space combat, guys...

Anything traveling at about 3 kilometers per second has as much kenetic energy as its equivilant mass in dynamite.

scifiideas.com/science-2/scifi-weapons-ballistic/

That looks about right.

Remember, at high enough velocities, all the little bits of the fly aren't going to have enough time to get out of the way of the plate before depositing their energy into a narrow cone going THROUGH it.

HEAT rounds use a shaped charge to reduce a conical sheet of copper to a narrow jet of plasma moving at about 14 km/s

(HEAT = High Explosive Anti Tank)

"Velocitas Eradico"

youtube.com/watch?v=n9CKhOf3BzY

Paint flecks have chipped glass on the space shuttle. You can damage and punch yourve as you through a harder material even if you couldn't scratch it on a hardness test.

You are tackling the problem too hard.

Let's slow down first and think about what is happening before throwing numbers around like a big boy.

How fast can the fly travel? That's the first question.

I was gonna post this
Just solve for the F the fly would need and you're done

About 90000 MPH, give or take some

The fly won't survive that velocity in its current form. It'll be converted into plasma instantaneously from the acceleration.

Point blank, it should work.

Use the stupid questions thread.

The fly can travel at whatever velocity imaginable.

I did, but then I solved for how much velocity would be needed to create a force that large by doing some equation rearranging.

This is not a stupid question. It is the quintessential form of modern physics and we need answers.

This does fall in between the calculated values of 27 and 54km/s at about 40km/s so that seems reasonable

So can we assume that the fly is moving through space, in a vacuum, and maybe is being accelerated by a tiny little magic rocket?

Because you try and make a fly do that in an earth atmosphere, the air will tear them to pieces and burn them up. Moving at that speed will generate so much resistance they'll vaporize and fall apart.

However, flying through space should have absolutely no effect. They could accumulate acceleration until they bonk into something or something in the opposite direction resists. So this experiment could be carried out there.

You should consider an object with the mass of the fly, and you should consider an object with the weight of the fly. The fly's mass is clearly not going to be enough UNLESS it's going so fast that, like above posts say, it impacts hard enough its essential parts make it a plasma at the point of impact.

If you gave a tiny object with the weight of the fly enough hardness to penetrate, you could scale it up with volume.

Engineer detected