Recent content by luxun2

Thanks for the replies guys.

So my dad got this Salt Crystal Lamp for a wedding gift that supposedly freshens the air naturally, and I need some help explaining to him why this doesn't actually work. It says on the box: "This lamp is scientifically proven to work like an air purifier. When lit, it can emit negative ions...

Nice answers thanks for the help all.

I do understand that we hear the whistling of air because of the edges but don't we hear sound come from the bullet vibrating itself too or is that negligent? I know its hard to tell it just being a video but how loud (dbs) do you imagine that the whistling itself to be, or can I calculate it...

Alrighty, well sound in my mind are the vibrations that propagate through air, water, and solids. If the bullet was shot then I would assume when it hit the target it became deformed like so(http://www.dreamstime.com/stock-image-deformed-flattened-out-bullets-image28978371) and therefore less...

This is my first post but just as it says in the title I'm curious about the physics behind falling objects. Specifically if you could examine this video which despite the title is not actually graphic and school me on why we heard what we did, Thanks. http://www.youtube.com/watch?v=0ABGIJwiGBc