Question about energy of a speeding object, hitting a stationary object.

[nukeman]

This might be a little hard to explain, but here we go :)

I want to mimic an astroid or celestial body hitting earth.

Lets not worry about effects from it going through the atmosphere or anything ok.

So, if I were to fire a bullet at an object that was the same density of Earth (5.2 g/cm^3) and the bullet was traveling at 3000 MPH, I would get a certain amount of destruction.

However, an asteroid would be going MUCH faster. For this, let's say the asteroid would be hitting the Earth at 10,000 MPH. Yes, I know they go much faster :)

Now, the only thing I am unable to change is the speed of the bullet, which is 3000 MPH.

How can I change things, so it would do the same level, or close to the level of destruction as the object going at 10,000 MPH? Change the density of the object I am hitting?

Any info would be great. Thanks much!

 

[K^2]

In high velocity impacts, materials behave more like fluids than solids, so your best bet is to try and match the Reynolds numbers. I'm not sure what you'd do for viscosity, though, since it will depend on energy released in impact. I suppose, if I was going to actually try this, I'd go for some loose sand-like material, and assume that dynamic viscosity will be roughly the same. Then I'd adjust density to match bullet's speed and size. I don't know if this will be any close, but it's the best idea I've got.

P.S. If you actually plan to try this with an actual fire arm, make sure you know what you're doing.