Got a physics question
 

If you're in some jet car going 1200fps forwards and you shoot a 1200fps bullet backwards, would the bullet just drop straight down from an observer's view? Let's say there's no other force acting on the bullet besides gravity after it gets fired.

Is this a serious question?

Would you be shooting at a relative?

:rolleyes:

I tried that once when I found my X-Wifes boyfriend. It didn't hit him, (maybe it dropped straight down) but it sure scared the S*** out of him. :rolleyes: :o :o

Earl, you continue to surprise me.:rolleyes:

Why were you looking for your Xwife's boyfriend at 1200fps? I estimate that at between 800 and 900 miles an hour.

If, somebody shoots at me, mine drops straight down too.

:D

I believe the bullet would travel at a reduced speed but not fall straight down as you are also moving foward. Get in the back of someones truck go 30-40mph and pitch a baseball, same effect ball will travel away from the vehicle until it hits the ground.

In all these types of "stepping off the plane when it crashes" questions, the first thing to consider is "the frame of reference". In this case, the frame of reference is the person holding the gun and the end of the barrel of the gun. The person holding the gun is stationary. It will leave the barrel at 1800fps.

As reasonable as it may sound that the bullet will exit the gun and "come to a dead stop", this is impossible with no other forces acting on it. If you happen to aim accurately at someone behind you while you travel at this speed. They will be shot....and shocked..... that you are that steady at that speed.

Our Earth is turning at an incredible speed, and basically turning in the direction of west toward east. Does the bullet go slower when we aim toward the east?

But that brings up another question. If the earth spins basically from west toward the east, why do storm systems and clouds basically travel from west toward east? Looks like the earth would spin and the clouds would be stationary above the earth, and appear to travel from east toward west.

I need beer.

are you taking in account the low and high pressure areas behind the car that would be created at that kind of speed?

You mean his wheels are on backwards? :eek: :D :D

Kinda like a fly in your car going 65mph, why doesnt the fly smack the back window?:D

Good one!! demonsvx gets the prize!! :D :D

Electrophil is making it way too complicated. The short answer, assuming that your 'observer' is not in the car with you and assuming that you fire the bullet as you pass by them, is yes.

Of course it will travel away from the truck.. duh. I'm talking will the bullet drop straight down relative to the Earth, where the observer is standing next to the road watching.

oh, the SRT-4?

This is a good question because it involves the concept of reference frames. The quick answer is that relative to you, the bullet will always travel at the same speed. In other reference frames, however, unexpected things can happen!

You may have heard of Newton's first law:

"Every body persists in its state of rest or of uniform motion in a straight line unless it is compelled to change that state by forces impressed on it."

We could rephrase this a little and say that a body in motion tends to stay in motion and a body at rest tends to stay at rest unless acted on by an external force.

Imagine you are on a perfectly smooth speeding train, moving at a uniform speed (not accelerating or turning), in a car with no windows. You would have no way of knowing how fast you are going (or if you were moving at all). If you throw a ball straight up in the air, it will come straight back down whether the train is sitting still or going 1,000 mph. Since you and the ball are already moving at the same speed as the train, the only forces acting on the ball are your hand and gravity. So the ball behaves exactly as it would if you were standing on the ground and not moving.

So what does this mean for our gun? If the gun shoots bullets at 1,000 mph, then the bullet will always move away from the gun at 1,000 mph. If you go to the front of a train that is moving at 1,000 mph and shoot the gun forward, the bullet will move away from you and the train at 1,000 mph, just as it would if the train were stopped. But, relative to the ground, the bullet will travel at 2,000 mph, the speed of the bullet plus the speed of the train. So if the bullet hits something on the ground, it will hit it going 2,000 mph.

If you shoot the bullet off the back of the train, the bullet will still be moving away from you and the gun at 1,000 mph, but now the speed of the train will subtract from the speed of the bullet. Relative to the ground, the bullet will not be moving at all, and it will drop straight to the ground.

Next question please :cool:

Not if the car is moving in reverse...the fly will still hit the windshield... :p