# The Naked Scientists Forum

### Author Topic: How does the speed and direction of a bullet change when it hits water?  (Read 3860 times)

#### Fitbike89

• First timers
• Posts: 5
##### How does the speed and direction of a bullet change when it hits water?
« on: 20/06/2008 15:51:20 »
Is it true that when a bullet is shot into water, it rapidly slows down and changes direction?

<Mod Edit - Subject formatted as a question.  Please try to do this to keep the forum tidy and easy to navigate - Thanks!>
« Last Edit: 20/06/2008 16:12:36 by BenV »

#### LeeE

• Neilep Level Member
• Posts: 3382
##### How does the speed and direction of a bullet change when it hits water?
« Reply #1 on: 20/06/2008 17:03:31 »
It certainly slows down, and very rapidly so, because the water is a lot denser than air.  As to how and if it changes direction - that'll depend upon a wide range of factors, from the shape of the bullet to the angle at which it hits the water.

#### texican

• First timers
• Posts: 1
##### How does the speed and direction of a bullet change when it hits water?
« Reply #2 on: 10/07/2008 16:05:15 »
A bullet, an arrow, or a stick will appear to change directions as it enters the water because the water bends the light rays differently than air. If you poke a stick in the water it will seem to change direction as it enters the water. It will angle further away from you. So, if you wanted to spear a fish or shoot one, you need to aim below the fish (if you are not under water yourself).
Objects in the water are closer than they appear.
« Last Edit: 10/07/2008 16:12:04 by texican »

#### AllenG

• Hero Member
• Posts: 503
##### How does the speed and direction of a bullet change when it hits water?
« Reply #3 on: 10/07/2008 22:00:44 »
American here.  There is a lot of stupid stuff we can get away with.

As a child my brother and I though it would be entertaining to shoot .22 caliber rifles into the deep end of the pool.
They made a big splash and when the water settled we could see our bullets laying on the floor of the pool several feet from where we had aimed.
Swimming to the bottom and rubbing our hand across the surface we could not feel any chips from where the bullets may have struck.

At this point we had the idea of one of us shooting into the deep end while the other was underwater in the shallow end watching, while wearing a diving mask so we could see the trajectories. When the bullet hit the water it would continue in a straight line dragging bubbles with it, but at seemingly random trajectories, and at up to forty five degrees divergent from the angle which it initially entered the water.

Furthermore by the time the bullets had traveled two or three feet through the water they had expended all of their energy, at which point they would start to sink straight downward.

We were wise enough not to lay on the bottom of the deep end and shooting at each other. Although we would probably have survived without injury, our mother did not raise complete idiots.
« Last Edit: 10/07/2008 22:04:20 by AllenG »

#### The Naked Scientists Forum

##### How does the speed and direction of a bullet change when it hits water?
« Reply #3 on: 10/07/2008 22:00:44 »